Don't create config cluster for existing dependents in simple cases

9 files changed, 546 insertions, 572 deletions

diff --git a/bpkg/pkg-build-collect.cxx b/bpkg/pkg-build-collect.cxx
index 159871b..3581a6b 100644
--- a/bpkg/pkg-build-collect.cxx
+++ b/bpkg/pkg-build-collect.cxx
@@ -1503,7 +1503,7 @@ namespace bpkg
     return &p;
   }
 
-  optional<vector<postponed_configuration::dependency>> build_packages::
+  optional<build_packages::pre_reevaluate_result> build_packages::
   collect_build_prerequisites (const pkg_build_options& options,
                                build_package& pkg,
                                build_package_refs& dep_chain,
@@ -1519,7 +1519,8 @@ namespace bpkg
                                postponed_dependencies& postponed_deps,
                                postponed_configurations& postponed_cfgs,
                                unacceptable_alternatives& unacceptable_alts,
-                               optional<pair<size_t, size_t>> reeval_pos)
+                               optional<pair<size_t, size_t>> reeval_pos,
+                               const optional<package_key>& orig_dep)
   {
     // NOTE: don't forget to update collect_build_postponed() if changing
     //       anything in this function. Also enable and run the tests with the
@@ -1536,7 +1537,11 @@ namespace bpkg
     bool pre_reeval (reeval_pos && reeval_pos->first == 0);
     assert (!pre_reeval || reeval_pos->second == 0);
 
-    bool reeval  (reeval_pos && reeval_pos->first != 0);
+    // Must only be specified in the pre-reevaluation mode.
+    //
+    assert (orig_dep.has_value () == pre_reeval);
+
+    bool reeval (reeval_pos && reeval_pos->first != 0);
     assert (!reeval || reeval_pos->second != 0);
 
     // The being (pre-)re-evaluated dependent cannot be recursively collected
@@ -1569,12 +1574,16 @@ namespace bpkg
         postponed_edeps.find (pk) == postponed_edeps.end ())
     {
       // Note that there can be multiple existing dependents for a dependency.
+      // Also note that we skip the existing dependents for which re-
+      // evaluation is optional not to initiate any negotiation in a simple
+      // case (see collect_build_prerequisites() description for details).
       //
       vector<existing_dependent> eds (
         query_existing_dependents (trace,
                                    options,
                                    pk.db,
                                    pk.name,
+                                   true /* exclude_optional */,
                                    fdb,
                                    rpt_depts,
                                    replaced_vers));
@@ -1693,15 +1702,14 @@ namespace bpkg
                                           postponed_cfgs);
           }
 
-          // Postpone the original dependency recursive collection if the
-          // existing dependent has deviated or the dependency belongs to the
-          // earliest depends clause with configuration clause or to some
-          // later depends clause. It is supposed that it will be collected
-          // during its existing dependent re-collection.
+          // Postpone the recursive collection of a dependency if the existing
+          // dependent has deviated or the dependency belongs to the earliest
+          // depends clause with configuration clause or to some later depends
+          // clause. It is supposed that it will be collected during its
+          // existing dependent re-collection.
           //
-          if (!ed.dependency               || // Dependent has deviated.
-              !ed.orig_dependency_position || // Later depends clause.
-              *ed.orig_dependency_position == ed.dependency_position)
+          if (!ed.dependency || // Dependent has deviated.
+              ed.originating_dependency_position >= ed.dependency_position)
           {
             postpone = true;
             postponed_edeps[pk].emplace_back (ed.db, ed.selected->name);
@@ -1873,7 +1881,23 @@ namespace bpkg
     bool postponed (false);
     bool reevaluated (false);
 
-    vector<postponed_configuration::dependency> r;
+    // In the pre-reevaluation mode keep track of configuration variable
+    // prefixes similar to what we do in pkg_configure_prerequisites(). Stop
+    // tracking if we discovered that the dependent re-evaluation is not
+    // optional.
+    //
+    vector<string> banned_var_prefixes;
+
+    auto references_banned_var = [&banned_var_prefixes] (const string& clause)
+    {
+      for (const string& p: banned_var_prefixes)
+      {
+        if (clause.find (p) != string::npos)
+          return true;
+      }
+
+      return false;
+    };
 
     if (pre_reeval)
     {
@@ -1896,10 +1920,12 @@ namespace bpkg
                       << " deviated: number of depends clauses changed to "
                       << nn << " from " << on;});
 
-        throw reeval_deviated ();
+        throw reevaluation_deviated ();
       }
     }
 
+    pre_reevaluate_result r;
+
     for (size_t di (sdeps.size ()); di != deps.size (); ++di)
     {
       // Fail if we missed the re-evaluation target position for any reason.
@@ -1932,7 +1958,7 @@ namespace bpkg
                           << ": toolchain buildtime dependency replaced the "
                           << " regular one with selected alternative " << oi;});
 
-            throw reeval_deviated ();
+            throw reevaluation_deviated ();
           }
         }
 
@@ -1958,8 +1984,23 @@ namespace bpkg
         {
           const dependency_alternative& da (das[i]);
 
-          if (!da.enable ||
-              skel.evaluate_enable (*da.enable, make_pair (di, i)))
+          bool enabled;
+
+          if (da.enable)
+          {
+            if (pre_reeval              &&
+                r.reevaluation_optional &&
+                references_banned_var (*da.enable))
+            {
+              r.reevaluation_optional = false;
+            }
+
+            enabled = skel.evaluate_enable (*da.enable, make_pair (di, i));
+          }
+          else
+            enabled = true;
+
+          if (enabled)
             edas.push_back (make_pair (ref (da), i));
         }
       }
@@ -1978,7 +2019,7 @@ namespace bpkg
                           << ": dependency with previously selected "
                           << "alternative " << oi << " is now disabled";});
 
-            throw reeval_deviated ();
+            throw reevaluation_deviated ();
           }
         }
 
@@ -2106,7 +2147,7 @@ namespace bpkg
                               << " is now in build system module "
                               << "configuration";});
 
-                throw reeval_deviated ();
+                throw reevaluation_deviated ();
               }
 
               assert (dr == nullptr); // Should fail on the "silent" run.
@@ -2173,7 +2214,7 @@ namespace bpkg
                 if (!wildcard (*dep_constr) &&
                     !satisfies (*dep_constr, dp.constraint))
                 {
-                  // We should end up throwing reeval_deviated exception
+                  // We should end up throwing reevaluation_deviated exception
                   // before the diagnostics run in the pre-reevaluation mode.
                   //
                   assert (!pre_reeval || dr == nullptr);
@@ -2279,7 +2320,7 @@ namespace bpkg
                                 << " deviated: package " << dn << *ddb
                                 << " is broken";});
 
-                  throw reeval_deviated ();
+                  throw reevaluation_deviated ();
                 }
 
                 assert (dr == nullptr); // Should fail on the "silent" run.
@@ -2414,7 +2455,7 @@ namespace bpkg
                                     << db->config_orig << ", "
                                     << ldb.config_orig;});
 
-                      throw reeval_deviated ();
+                      throw reevaluation_deviated ();
                     }
 
                     assert (dr == nullptr); // Should fail on the "silent" run.
@@ -2448,7 +2489,7 @@ namespace bpkg
                                 << "is found for build-time dependency ("
                                 << dp << ')';});
 
-                  throw reeval_deviated ();
+                  throw reevaluation_deviated ();
                 }
 
                 // The private config should be created on the "silent" run
@@ -2560,7 +2601,7 @@ namespace bpkg
                               << "module " << dn << " in its dependent "
                               << "package configuration " << pdb.config_orig;});
 
-                throw reeval_deviated ();
+                throw reevaluation_deviated ();
               }
 
               assert (dr == nullptr); // Should fail on the "silent" run.
@@ -2596,7 +2637,7 @@ namespace bpkg
                                 << pkg.available_name_version_db ()
                                 << " deviated: is now orphaned";});
 
-                  throw reeval_deviated ();
+                  throw reevaluation_deviated ();
                 }
 
                 assert (dr == nullptr); // Should fail on the "silent" run.
@@ -2675,7 +2716,7 @@ namespace bpkg
                                 << (!dep_constr ? "" : "user-specified ")
                                 << "dependency constraint (" << d << ')';});
 
-                  throw reeval_deviated ();
+                  throw reevaluation_deviated ();
                 }
 
                 if (dep_constr && !system && postponed_repo != nullptr)
@@ -2774,7 +2815,7 @@ namespace bpkg
                 //
                 if (dap->system_version (*ddb) == nullptr)
                 {
-                  // We should end up throwing reeval_deviated exception
+                  // We should end up throwing reevaluation_deviated exception
                   // before the diagnostics run in the pre-reevaluation mode.
                   //
                   assert (!pre_reeval || dr == nullptr);
@@ -2790,7 +2831,7 @@ namespace bpkg
 
                 if (!satisfies (*dap->system_version (*ddb), d.constraint))
                 {
-                  // We should end up throwing reeval_deviated exception
+                  // We should end up throwing reevaluation_deviated exception
                   // before the diagnostics run in the pre-reevaluation mode.
                   //
                   assert (!pre_reeval || dr == nullptr);
@@ -2880,7 +2921,7 @@ namespace bpkg
                     {
                       if (!satisfies (v1, c2.value))
                       {
-                        // We should end up throwing reeval_deviated exception
+                        // We should end up throwing reevaluation_deviated exception
                         // before the diagnostics run in the pre-reevaluation
                         // mode.
                         //
@@ -3691,6 +3732,7 @@ namespace bpkg
                                                   options,
                                                   d.db,
                                                   d.name,
+                                                  false /* exclude_optional */,
                                                   fdb,
                                                   rpt_depts,
                                                   replaced_vers))
@@ -3944,31 +3986,101 @@ namespace bpkg
         };
 
       // Select a dependency alternative, copying it alone into the resulting
-      // dependencies list and evaluating its reflect clause, if present.
+      // dependencies list and evaluating its reflect clause, if present. In
+      // the pre-reevaluation mode update the variable prefixes list, if the
+      // selected alternative has config clause, and the pre-reevaluation
+      // resulting information (re-evaluation position, etc).
+      //
+      // Note that prebuilds are only used in the pre-reevaluation mode.
       //
       bool selected (false);
-      auto select = [&sdeps, &salts, &sdas, &skel, di, &selected]
-        (const dependency_alternative& da, size_t dai)
+      auto select = [&sdeps, &salts, &sdas,
+                     &skel,
+                     di,
+                     &selected,
+                     pre_reeval, &banned_var_prefixes, &references_banned_var,
+                     &orig_dep,
+                     &r] (const dependency_alternative& da,
+                          size_t dai,
+                          prebuilds&& pbs)
+      {
+        assert (sdas.empty ());
+
+        if (pre_reeval)
         {
-          assert (sdas.empty ());
+          pair<size_t, size_t> pos (di + 1, dai + 1);
 
-          // Avoid copying enable/reflect not to evaluate them repeatedly.
+          bool contains_orig_dep (
+            find_if (pbs.begin (), pbs.end (),
+                     [&orig_dep] (const prebuild& pb)
+                     {
+                       return pb.dependency.name == orig_dep->name &&
+                              pb.db == orig_dep->db;
+                     }) != pbs.end ());
+
+          // If the selected alternative contains the originating dependency,
+          // then set the originating dependency position, unless it is
+          // already set (note that the same dependency package may
+          // potentially be specified in multiple depends clauses).
           //
-          sdas.emplace_back (nullopt /* enable */,
-                             nullopt /* reflect */,
-                             da.prefer,
-                             da.accept,
-                             da.require,
-                             da /* dependencies */);
+          if (contains_orig_dep && r.originating_dependency_position.first == 0)
+            r.originating_dependency_position = pos;
 
-          sdeps.push_back (move (sdas));
-          salts.push_back (dai);
+          if (da.prefer || da.require)
+          {
+            if (contains_orig_dep)
+              r.reevaluation_optional = false;
 
-          if (da.reflect)
-            skel.evaluate_reflect (*da.reflect, make_pair (di, dai));
+            // If this is the first selected alternative with the config
+            // clauses, then save its position and the dependency packages.
+            //
+            if (r.reevaluation_position.first == 0)
+            {
+              r.reevaluation_position = pos;
 
-          selected = true;
-        };
+              for (prebuild& pb: pbs)
+                r.reevaluation_dependencies.emplace_back (
+                  pb.db, move (pb.dependency.name));
+            }
+
+            // Save the variable prefixes for the selected alternative
+            // dependencies, if we still track them.
+            //
+            if (r.reevaluation_optional)
+            {
+              for (const dependency& d: da)
+                banned_var_prefixes.push_back (
+                  "config." + d.name.variable () + '.');
+            }
+          }
+        }
+
+        // Avoid copying enable/reflect not to evaluate them repeatedly.
+        //
+        sdas.emplace_back (nullopt /* enable */,
+                           nullopt /* reflect */,
+                           da.prefer,
+                           da.accept,
+                           da.require,
+                           da /* dependencies */);
+
+        sdeps.push_back (move (sdas));
+        salts.push_back (dai);
+
+        if (da.reflect)
+        {
+          if (pre_reeval              &&
+              r.reevaluation_optional &&
+              references_banned_var (*da.reflect))
+          {
+            r.reevaluation_optional = false;
+          }
+
+          skel.evaluate_reflect (*da.reflect, make_pair (di, dai));
+        }
+
+        selected = true;
+      };
 
       // Postpone the prerequisite builds collection, optionally inserting the
       // package to the postponements set (can potentially already be there)
@@ -4039,18 +4151,6 @@ namespace bpkg
         //
         bool reused_only (false);
 
-        auto pre_reeval_append_result = [&r] (pair<size_t, size_t> pos,
-                                              prebuilds&& builds)
-        {
-          postponed_configuration::packages deps;
-          deps.reserve (builds.size ());
-
-          for (prebuild& b: builds)
-            deps.emplace_back (b.db, move (b.dependency.name));
-
-          r.emplace_back (pos, move (deps), nullopt /* has_alternative */);
-        };
-
         for (size_t i (0); i != edas.size (); ++i)
         {
           // Skip the unacceptable alternatives.
@@ -4142,9 +4242,7 @@ namespace bpkg
                              &trace,
                              &postpone,
                              &collect,
-                             &select,
-                             &pre_reeval_append_result]
-                            (size_t index, precollect_result&& pcr)
+                             &select] (size_t index, precollect_result&& pcr)
           {
             const auto& eda (edas[index]);
             const dependency_alternative& da (eda.first);
@@ -4192,16 +4290,7 @@ namespace bpkg
                                 << ": selected alternative changed to " << ni
                                 << " from " << oi;});
 
-                  throw reeval_deviated ();
-                }
-
-                pre_reeval_append_result (make_pair (di + 1, ni),
-                                          move (*pcr.builds));
-
-                if (da.prefer || da.require)
-                {
-                  postpone (nullptr);
-                  return true;
+                  throw reevaluation_deviated ();
                 }
               }
               else if (!collect (da, dai, move (*pcr.builds), prereqs))
@@ -4210,7 +4299,7 @@ namespace bpkg
                 return true;
               }
 
-              select (da, dai);
+              select (da, dai, move (*pcr.builds));
 
               // Make sure no more true alternatives are selected during this
               // function call unless we are (pre-)reevaluating a dependent.
@@ -4284,16 +4373,7 @@ namespace bpkg
                               << ": selected alternative (single) changed to "
                               << ni << " from " << oi;});
 
-                  throw reeval_deviated ();
-              }
-
-              pre_reeval_append_result (make_pair (di + 1, ni),
-                                        move (*pcr.builds));
-
-              if (da.prefer || da.require)
-              {
-                postpone (nullptr);
-                break;
+                  throw reevaluation_deviated ();
               }
             }
             else if (!collect (da, dai, move (*pcr.builds), prereqs))
@@ -4302,7 +4382,7 @@ namespace bpkg
               break;
             }
 
-            select (da, dai);
+            select (da, dai, move (*pcr.builds));
           }
         }
 
@@ -4329,7 +4409,7 @@ namespace bpkg
                           << ": now can't select alternative, previously "
                           << oi << " was selected";});
 
-            throw reeval_deviated ();
+            throw reevaluation_deviated ();
           }
 
           if (reeval)
@@ -4445,7 +4525,15 @@ namespace bpkg
         }
       }
 
-      if (postponed)
+      // Bail out if the collection is postponed or we are in the
+      // pre-reevaluation mode and have already collected all the required
+      // information.
+      //
+      if (postponed ||
+          (pre_reeval                                   &&
+           r.reevaluation_position.first != 0           &&
+           r.originating_dependency_position.first != 0 &&
+           !r.reevaluation_optional))
         break;
     }
 
@@ -4459,18 +4547,34 @@ namespace bpkg
 
     if (pre_reeval)
     {
+      // It doesn't feel like it may happen in the pre-reevaluation mode. If
+      // it still happens, maybe due to some manual tampering, let's assume
+      // this as a deviation case.
+      //
+      if (r.originating_dependency_position.first == 0)
+      {
+        l5 ([&]{trace << "re-evaluation of dependent "
+                      << pkg.available_name_version_db ()
+                      << " deviated: previously selected dependency "
+                      << *orig_dep << " is not selected anymore";});
+
+        throw reevaluation_deviated ();
+      }
+
       l5 ([&]
           {
             diag_record dr (trace);
             dr << "pre-reevaluated " << pkg.available_name_version_db ()
                << ": ";
 
-            if (postponed)
+            pair<size_t, size_t> pos (r.reevaluation_position);
+
+            if (pos.first != 0)
             {
-              assert (!r.empty ());
+              dr << pos.first << ',' << pos.second;
 
-              dr << r.back ().position.first << ','
-                 << r.back ().position.second;
+              if (r.reevaluation_optional)
+                dr << " re-evaluation is optional";
             }
             else
               dr << "end reached";
@@ -4486,9 +4590,9 @@ namespace bpkg
                     << pkg.available_name_version_db ();});
     }
 
-    return pre_reeval && postponed
-           ? optional<vector<postponed_configuration::dependency>> (move (r))
-           : nullopt;
+    return pre_reeval && r.reevaluation_position.first != 0
+           ? move (r)
+           : optional<pre_reevaluate_result> ();
   }
 
   void build_packages::
@@ -5002,6 +5106,7 @@ namespace bpkg
                                               o,
                                               p.db,
                                               p.name,
+                                              false /* exclude_optional */,
                                               fdb,
                                               rpt_depts,
                                               replaced_vers))
@@ -6104,6 +6209,7 @@ namespace bpkg
                                             o,
                                             pk.db,
                                             pk.name,
+                                            false /* exclude_optional */,
                                             fdb,
                                             rpt_depts,
                                             replaced_vers))
@@ -6712,6 +6818,7 @@ namespace bpkg
     const pkg_build_options& o,
     database& db,
     const package_name& name,
+    bool exclude_optional,
     const function<find_database_function>& fdb,
     const repointed_dependents& rpt_depts,
     const replaced_versions& replaced_vers)
@@ -6828,6 +6935,8 @@ namespace bpkg
              lazy_shared_ptr<repository_fragment>> rp (
                find_available_fragment (o, ddb, dsp));
 
+        optional<package_key> orig_dep (package_key {db, name});
+
         try
         {
           build_package p {
@@ -6865,7 +6974,7 @@ namespace bpkg
           unacceptable_alternatives unacceptable_alts;
           replaced_versions replaced_vers;
 
-          optional<vector<postponed_configuration::dependency>> deps (
+          optional<pre_reevaluate_result> pr (
             collect_build_prerequisites (o,
                                          p,
                                          dep_chain,
@@ -6881,7 +6990,8 @@ namespace bpkg
                                          postponed_deps,
                                          postponed_cfgs,
                                          unacceptable_alts,
-                                         pair<size_t, size_t> (0, 0)));
+                                         pair<size_t, size_t> (0, 0),
+                                         orig_dep));
 
           // Must be read-only.
           //
@@ -6894,49 +7004,36 @@ namespace bpkg
                   unacceptable_alts.empty () &&
                   replaced_vers.empty ());
 
-          if (deps)
+          if (pr && (!pr->reevaluation_optional || !exclude_optional))
           {
-            package_key pk {db, name};
-
-            assert (!deps->empty ());
-
-            // Try to retrieve the original dependency position. If we fail,
-            // then this dependency belongs to the depends clause which comes
-            // after the re-evaluation target position.
-            //
-            optional<pair<size_t, size_t>> odp;
-
-            for (const postponed_configuration::dependency& d: *deps)
-            {
-              if (find (d.begin (), d.end (), pk) != d.end ())
-              {
-                odp = d.position;
-                break;
-              }
-            }
-
-            // Try to preserve the name of the original dependency as the one
-            // which brings the existing dependent to the config cluster.
+            // Try to preserve the name of the originating dependency as the
+            // one which brings the existing dependent to the config cluster.
             // Failed that, use the first dependency in the alternative which
             // we will be re-evaluating to.
             //
-            postponed_configuration::dependency& d (deps->back ());
+            package_key dep (*orig_dep);
+
+            pre_reevaluate_result::packages& deps (
+              pr->reevaluation_dependencies);
+
+            assert (!deps.empty ());
 
-            if (find (d.begin (), d.end (), pk) == d.end ())
-              pk = move (d.front ());
+            if (find (deps.begin (), deps.end (), dep) == deps.end ())
+              dep = move (deps.front ());
 
             r.push_back (
-              existing_dependent {ddb, move (dsp),
-                                  move (pk), d.position,
-                                  package_key {db, name}, odp});
+              existing_dependent {
+                ddb, move (dsp),
+                move (dep), pr->reevaluation_position,
+                move (*orig_dep), pr->originating_dependency_position});
           }
         }
-        catch (const reeval_deviated&)
+        catch (const reevaluation_deviated&)
         {
           r.push_back (
             existing_dependent {ddb, move (dsp),
                                 nullopt, {},
-                                package_key {db, name}, nullopt});
+                                move (*orig_dep), {}});
         }
       }
     }
@@ -7080,23 +7177,23 @@ namespace bpkg
       ed.selected,
       move (rp.first),
       move (rp.second),
-      nullopt,                    // Dependencies.
-      nullopt,                    // Dependencies alternatives.
-      nullopt,                    // Package skeleton.
-      nullopt,                    // Postponed dependency alternatives.
-      false,                      // Recursive collection.
-      nullopt,                    // Hold package.
-      nullopt,                    // Hold version.
-      {},                         // Constraints.
-      false,                      // System.
-      false,                      // Keep output directory.
-      false,                      // Disfigure (from-scratch reconf).
-      false,                      // Configure-only.
-      nullopt,                    // Checkout root.
-      false,                      // Checkout purge.
-      strings (),                 // Configuration variables.
-      {ed.orig_dependency},       // Required by (dependency).
-      false,                      // Required by dependents.
+      nullopt,                     // Dependencies.
+      nullopt,                     // Dependencies alternatives.
+      nullopt,                     // Package skeleton.
+      nullopt,                     // Postponed dependency alternatives.
+      false,                       // Recursive collection.
+      nullopt,                     // Hold package.
+      nullopt,                     // Hold version.
+      {},                          // Constraints.
+      false,                       // System.
+      false,                       // Keep output directory.
+      false,                       // Disfigure (from-scratch reconf).
+      false,                       // Configure-only.
+      nullopt,                     // Checkout root.
+      false,                       // Checkout purge.
+      strings (),                  // Configuration variables.
+      {ed.originating_dependency}, // Required by (dependency).
+      false,                       // Required by dependents.
       flags};
 
     // Note: not recursive.
diff --git a/bpkg/pkg-build-collect.hxx b/bpkg/pkg-build-collect.hxx
index 1c3bc09..d3bcb79 100644
--- a/bpkg/pkg-build-collect.hxx
+++ b/bpkg/pkg-build-collect.hxx
@@ -1248,15 +1248,31 @@ namespace bpkg
     // exception if such a cycle is detected.
     //
     // If {0,0} is specified as the reeval_pos argument, then perform the
-    // pre-reevaluation. In this read-only mode perform the regular dependency
-    // alternative selection but not the actual dependency collection and stop
-    // when all the depends clauses are processed or an alternative with the
-    // configuration clause is encountered. In the latter case return the list
-    // of the selected alternative dependencies/positions, where the last
-    // entry corresponds to the alternative with the encountered configuration
-    // clause. Return nullopt otherwise. Also look for any deviation in the
-    // dependency alternatives selection and throw reeval_deviated exception
-    // if such a deviation is detected.
+    // pre-reevaluation of an existing dependent, requested due to the
+    // specific dependency up/down-grade or reconfiguration (must be passed as
+    // the orig_dep; we call it originating dependency). The main purpose of
+    // this read-only mode is to obtain the position of the earliest selected
+    // dependency alternative with the config clause, if any, which the
+    // re-evaluation needs to be performed to and to determine if such a
+    // re-evaluation is optional (see pre_reevaluate_result for the full
+    // information being retrieved). The re-evaluation is considered to be
+    // optional if the existing dependent has no config clause for the
+    // originating dependency and the enable and reflect clauses do not refer
+    // to any of the dependency configuration variables (which can only be
+    // those which the dependent has the configuration clauses for; see the
+    // bpkg manual for details). The thinking here is that such an existing
+    // dependent may not change any configuration it applies to its
+    // dependencies and thus it doesn't call for any negotiations (note: if
+    // there are config clauses for the upgraded originating dependency, then
+    // the potentially different defaults for its config variables may affect
+    // the configuration this dependent applies to its dependencies). Such a
+    // dependent can also be reconfigured without pre-selection of its
+    // dependency alternatives since pkg-configure is capable of doing that on
+    // its own for such a simple case (see pkg_configure_prerequisites() for
+    // details). Also look for any deviation in the dependency alternatives
+    // selection and throw reevaluation_deviated exception if such a deviation
+    // is detected. Return nullopt if no dependency alternative with the
+    // config clause is selected.
     //
     // If the package is a dependency of configured dependents and needs to be
     // reconfigured (being upgraded, has configuration specified, etc), then
@@ -1319,9 +1335,19 @@ namespace bpkg
       size_t depth;
     };
 
-    struct reeval_deviated {};
+    struct reevaluation_deviated {};
 
-    optional<vector<postponed_configuration::dependency>>
+    struct pre_reevaluate_result
+    {
+      using packages = postponed_configuration::packages;
+
+      pair<size_t, size_t> reevaluation_position;
+      packages             reevaluation_dependencies;
+      bool                 reevaluation_optional = true;
+      pair<size_t, size_t> originating_dependency_position;
+    };
+
+    optional<pre_reevaluate_result>
     collect_build_prerequisites (const pkg_build_options&,
                                  build_package&,
                                  build_package_refs& dep_chain,
@@ -1337,7 +1363,8 @@ namespace bpkg
                                  postponed_dependencies&,
                                  postponed_configurations&,
                                  unacceptable_alternatives&,
-                                 optional<pair<size_t, size_t>> reeval_pos = nullopt);
+                                 optional<pair<size_t, size_t>> reeval_pos = nullopt,
+                                 const optional<package_key>& orig_dep = nullopt);
 
     void
     collect_build_prerequisites (const pkg_build_options&,
@@ -1476,28 +1503,26 @@ namespace bpkg
     // in the map) or expected to be built or dropped (present in rpt_depts or
     // replaced_vers). Also skip dependents which impose the version
     // constraint on this dependency and the dependency doesn't satisfy this
-    // constraint.
+    // constraint. Optionally, skip the existing dependents for which
+    // re-evaluation is considered optional (exclude_optional argument; see
+    // pre-reevaluation mode of collect_build_prerequisites() for details).
     //
     struct existing_dependent
     {
       // Dependent.
       //
-      reference_wrapper<database>    db;
-      shared_ptr<selected_package>   selected;
+      reference_wrapper<database>  db;
+      shared_ptr<selected_package> selected;
 
       // Earliest dependency with config clause.
       //
-      optional<package_key>          dependency;
-      pair<size_t, size_t>           dependency_position;
+      optional<package_key>        dependency;
+      pair<size_t, size_t>         dependency_position;
 
-      // Original dependency.
-      //
-      // Note that we always know the original dependency but may not be able
-      // to obtain its position if it comes after the earliest dependency with
-      // config clause or the dependent deviates.
+      // Originating dependency passed to the function call.
       //
-      package_key                    orig_dependency;
-      optional<pair<size_t, size_t>> orig_dependency_position;
+      package_key                  originating_dependency;
+      pair<size_t, size_t>         originating_dependency_position;
     };
 
     // This exception is thrown by collect_build_prerequisites() and
@@ -1517,6 +1542,7 @@ namespace bpkg
       const pkg_build_options&,
       database&,
       const package_name&,
+      bool exclude_optional,
       const function<find_database_function>&,
       const repointed_dependents&,
       const replaced_versions&);
diff --git a/tests/common/dependency-alternatives/t11a/bax-1.0.0.tar.gz b/tests/common/dependency-alternatives/t11a/bax-1.0.0.tar.gz
index d488f1a..6c00903 100644
--- a/tests/common/dependency-alternatives/t11a/bax-1.0.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/bax-1.0.0.tar.gz
diff --git a/tests/common/dependency-alternatives/t11a/bus-0.1.0.tar.gz b/tests/common/dependency-alternatives/t11a/bus-0.1.0.tar.gz
index e486d37..e3672b2 100644
--- a/tests/common/dependency-alternatives/t11a/bus-0.1.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/bus-0.1.0.tar.gz
diff --git a/tests/common/dependency-alternatives/t11a/foo-1.0.0.tar.gz b/tests/common/dependency-alternatives/t11a/foo-1.0.0.tar.gz
index c9a4d6d..42d9cc5 100644
--- a/tests/common/dependency-alternatives/t11a/foo-1.0.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/foo-1.0.0.tar.gz
diff --git a/tests/common/dependency-alternatives/t11a/fox-1.0.0.tar.gz b/tests/common/dependency-alternatives/t11a/fox-1.0.0.tar.gz
index 17b7278..159cfbd 100644
--- a/tests/common/dependency-alternatives/t11a/fox-1.0.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/fox-1.0.0.tar.gz
diff --git a/tests/common/dependency-alternatives/t11a/tex-1.0.0.tar.gz b/tests/common/dependency-alternatives/t11a/tex-1.0.0.tar.gz
index 3c9093d..0c9e29d 100644
--- a/tests/common/dependency-alternatives/t11a/tex-1.0.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/tex-1.0.0.tar.gz
diff --git a/tests/common/dependency-alternatives/t11a/tiz-1.0.0.tar.gz b/tests/common/dependency-alternatives/t11a/tiz-1.0.0.tar.gz
index 63c5876..8bfadcd 100644
--- a/tests/common/dependency-alternatives/t11a/tiz-1.0.0.tar.gz
+++ b/tests/common/dependency-alternatives/t11a/tiz-1.0.0.tar.gz
diff --git a/tests/pkg-build.testscript b/tests/pkg-build.testscript
index 99636ad..b6aadba 100644
--- a/tests/pkg-build.testscript
+++ b/tests/pkg-build.testscript
@@ -205,7 +205,7 @@
 # |   |-- libbiz-1.0.0.tar.gz   -> libbar
 # |   |-- foo-0.1.0.tar.gz      -> libfoo {require {config.libfoo.extras=true}}
 # |   |-- foo-0.2.0.tar.gz      -> libfoo {require {config.libfoo.extras=true}} | libbar
-# |   |-- foo-1.0.0.tar.gz      -> libfoo {require {config.libfoo.extras=true}}
+# |   |-- foo-1.0.0.tar.gz      -> libfoo {require {config.libfoo.extras=true} reflect {...}}
 # |   |-- fox-0.1.0.tar.gz      -> libfoo {prefer {config.libfoo.extras=true} accept (false)} |
 # |   |                            libbar
 # |   |-- fox-0.2.0.tar.gz      -> libfoo {prefer {config.libfoo.extras=false} accept (!$config.libfoo.extras)} |
@@ -226,7 +226,7 @@
 # |   |-- bat-1.0.0.tar.gz      -> libbaz {require {config.libbaz.extras=true}}
 # |   |-- bas-1.0.0.tar.gz      -> libbar {require {config.libbar.extras=true}},
 # |   |                            bus {require {config.bus.extras=true}}
-# |   |-- bus-0.1.0.tar.gz      -> foo {require {config.foo.extras=true}}
+# |   |-- bus-0.1.0.tar.gz      -> foo {require {config.foo.extras=true} reflect {...}}
 # |   |-- bus-1.0.0.tar.gz      -> libaz {require {config.libbaz.extras=true}},
 # |   |                            foo {require {config.foo.extras=true}}
 # |   |-- box-0.1.0.tar.gz      -> libbox == 0.1.0 {require {config.libbox.extras=true}}
@@ -234,7 +234,7 @@
 # |   |-- box-1.0.0.tar.gz      -> {libbar libfoo} {require {config.libbar.extras=true config.libfoo.extras=true}} |
 # |   |                            libbox
 # |   |-- bax-0.1.0.tar.gz      -> {libbox libbar} {require {config.libbox.extras=true}}
-# |   |-- bax-1.0.0.tar.gz      -> libfoo {require {config.libfoo.extras=true}},
+# |   |-- bax-1.0.0.tar.gz      -> libfoo {require {config.libfoo.extras=true} reflect {...}},
 # |   |                            {libbox libbar} {require {config.libbox.extras=true config.libbar.extras=true}}
 # |   |-- bux-1.0.0.tar.gz      -> libbar {require {config.libbar.extras=true}}
 # |   |-- bix-1.0.0.tar.gz      -> {libbar bar} {require {config.libbar.extras=true config.bar.extras=true}},
@@ -254,11 +254,11 @@
 # |   |-- tex-0.3.0.tar.gz      -> libbar {require {config.libbar.extras=true}},
 # |   |                            libfoo {require {config.libfoo.extras=true}}
 # |   |-- tex-1.0.0.tar.gz      -> libbar {require {config.libbar.extras=true}},
-# |   |                            libfoo {require {config.libfoo.extras=true}}
+# |   |                            libfoo {require {config.libfoo.extras=true} reflect {...}}
 # |   |-- tix-0.1.0.tar.gz
 # |   |-- tix-1.0.0.tar.gz      -> libbar {require {config.libbar.extras=true}},
 # |   |                            tex {require {config.tex.extras=true}}
-# |   |-- tiz-1.0.0.tar.gz      -> tex {require {config.tex.extras=true}},
+# |   |-- tiz-1.0.0.tar.gz      -> tex {require {config.tex.extras=true}, reflect {...}},
 # |   |                            libbar {require {config.libbar.extras=true}}
 # |   |-- toz-0.1.0.tar.gz
 # |   |-- toz-0.2.0.tar.gz      -> libfoo {require {config.libfoo.extras=true}},
@@ -5755,33 +5755,27 @@ test.arguments += --sys-no-query
         #
         #  fux: depends: libfoo
         #
-        $* foo fox fux 2>>~%EOE%;
+        $* foo fox fux 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/1.0.0
           trace: collect_build: add fux/1.0.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/1.0.0
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone fox/1.0.0
           trace: collect_build_prerequisites: begin fux/1.0.0
-          %.*
           trace: collect_build_prerequisites: dep-postpone dependency libfoo/1.0.0 of dependent fux/1.0.0 since already in cluster {foo fox | libfoo->{foo/1,1 fox/1,1}}
           trace: collect_build_prerequisites: end fux/1.0.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo fox | libfoo->{foo/1,1 fox/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo fox | libfoo->{foo/1,1 fox/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -5801,7 +5795,9 @@ test.arguments += --sys-no-query
             new libfoo/1.0.0 (required by foo, fox, fux)
               config.libfoo.extras=true (set by foo)
             new foo/1.0.0
+              config.foo.libfoo_extras=true (set by foo)
             new fox/1.0.0
+              config.fox.libfoo_extras=true (set by fox)
             new fux/1.0.0
           %.*
           EOE
@@ -5823,28 +5819,22 @@ test.arguments += --sys-no-query
       {
         $clone_cfg;
 
-        $* foo fox '?sys:libfoo/*' 2>>~%EOE%;
+        $* foo fox '?sys:libfoo/*' 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/1.0.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency sys:libfoo/* of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency sys:libfoo/* of dependent fox/1.0.0
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone fox/1.0.0
-          %.*
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo fox | libfoo->{foo/1,1 fox/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo fox | libfoo->{foo/1,1 fox/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: skip system sys:libfoo/*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
@@ -5857,14 +5847,15 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): cfg-negotiate end {foo fox | libfoo->{foo/1,1 fox/1,1}}!
           trace: collect_build_postponed (1): end {foo fox | libfoo->{foo/1,1 fox/1,1}}
           trace: collect_build_postponed (0): end
-          %.*
           trace: execute_plan: simulate: yes
           %.*
           build plan:
             configure sys:libfoo/* (required by foo, fox)
               config.libfoo.extras=true (expected by foo)
             new foo/1.0.0
+              config.foo.libfoo_extras=true (set by foo)
             new fox/1.0.0
+              config.fox.libfoo_extras=true (set by fox)
           %.*
           EOE
 
@@ -5883,27 +5874,23 @@ test.arguments += --sys-no-query
       {
         $clone_cfg;
 
-        $* foo bar baz 2>>~%EOE%;
+        $* foo bar baz 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add bar/1.0.0
           trace: collect_build: add baz/1.0.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin bar/1.0.0
-          %.*
           trace: collect_build: add libbar/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bar/1.0.0
           trace: postponed_configurations::add: create {bar | libbar->{bar/1,1}}
           trace: collect_build_prerequisites: postpone bar/1.0.0
           trace: collect_build_prerequisites: begin baz/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent baz/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent baz/1.0.0
           trace: postponed_configurations::add: add {baz 1,1: libbar libfoo} to {foo | libfoo->{foo/1,1}}
@@ -5911,9 +5898,7 @@ test.arguments += --sys-no-query
           trace: collect_build_prerequisites: postpone baz/1.0.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {bar baz foo | libfoo->{baz/1,1 foo/1,1} libbar->{bar/1,1 baz/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {bar baz foo | libfoo->{baz/1,1 foo/1,1} libbar->{bar/1,1 baz/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -5938,6 +5923,7 @@ test.arguments += --sys-no-query
             new libfoo/1.0.0 (required by baz, foo)
               config.libfoo.extras=true (set by baz)
             new foo/1.0.0
+              config.foo.libfoo_extras=true (set by foo)
             new libbar/1.0.0 (required by bar, baz)
               config.libbar.extras=true (set by bar)
             new bar/1.0.0
@@ -6105,69 +6091,54 @@ test.arguments += --sys-no-query
         #
         #  fix: depends: foo(c)
         #
-        $* fux foo fix 2>>~%EOE%;
+        $* fux foo fix 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add fux/1.0.0
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fix/1.0.0
           trace: collect_build_prerequisites: begin fux/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: no cfg-clause for dependency libfoo/1.0.0 of dependent fux/1.0.0
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
           trace: collect_build_prerequisites: end fux/1.0.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build_prerequisites: cannot cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0 (collected prematurely), throwing postpone_dependency
           trace: pkg_build: collection failed due to prematurely collected dependency (libfoo), retry from scratch
-          %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add fux/1.0.0
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fix/1.0.0
           trace: collect_build_prerequisites: begin fux/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: dep-postpone dependency libfoo/1.0.0 of dependent fux/1.0.0
           trace: collect_build_prerequisites: end fux/1.0.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fix/1.0.0
-          %.*
           trace: collect_build_prerequisites: cannot cfg-postpone dependency foo/1.0.0 of dependent fix/1.0.0 (collected prematurely), throwing postpone_dependency
           trace: pkg_build: collection failed due to prematurely collected dependency (foo), retry from scratch
-          %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add fux/1.0.0
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fix/1.0.0
           trace: collect_build_prerequisites: begin fux/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: dep-postpone dependency libfoo/1.0.0 of dependent fux/1.0.0
           trace: collect_build_prerequisites: end fux/1.0.0
           trace: pkg_build: dep-postpone user-specified foo
           trace: collect_build_prerequisites: begin fix/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency foo/1.0.0 of dependent fix/1.0.0
           trace: postponed_configurations::add: create {fix | foo->{fix/1,1}}
           trace: collect_build_prerequisites: postpone fix/1.0.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {fix | foo->{fix/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {fix | foo->{fix/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
@@ -6177,9 +6148,7 @@ test.arguments += --sys-no-query
           trace: collect_build_prerequisites: end fix/1.0.0
           trace: collect_build_postponed (1): cfg-negotiate end {fix | foo->{fix/1,1}}!
           trace: collect_build_postponed (2): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (2): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -6199,6 +6168,7 @@ test.arguments += --sys-no-query
             new fux/1.0.0
             new foo/1.0.0
               config.foo.extras=true (set by fix)
+              config.foo.libfoo_extras=true (set by foo)
             new fix/1.0.0
           trace: execute_plan: simulate: no
           %.*
@@ -6568,18 +6538,13 @@ test.arguments += --sys-no-query
               !libfoo configured !0.1.0 available 1.0.0
             EOO
 
-          $* libfoo 2>>~%EOE%;
+          $* libfoo 2>&1 | $filter 2>>~%EOE%;
             %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval foo/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated foo/1.0.0: 1,1
-            %.*
             trace: collect_build_prerequisites: pre-reeval fox/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated fox/1.0.0: 1,1
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of existing dependent foo/1.0.0 due to dependency libfoo/1.0.0
             trace: collect_build: add foo/1.0.0
@@ -6588,28 +6553,22 @@ test.arguments += --sys-no-query
             trace: collect_build: add fox/1.0.0
             trace: collect_build_postponed (0): begin
             trace: collect_build_postponed (1): begin {foo^ | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_prerequisites: pre-reeval foo/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated foo/1.0.0: 1,1
             trace: collect_build_prerequisites: pre-reeval fox/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated fox/1.0.0: 1,1
             trace: collect_build_postponed (1): re-evaluate existing dependents for {foo^ | libfoo->{foo/1,1}}
             trace: collect_build_prerequisites: reeval foo/1.0.0
-            %.*
             trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
             trace: postponed_configurations::add: add {foo^ 1,1: libfoo} to {foo^ | libfoo->{foo/1,1}}
             trace: collect_build_prerequisites: re-evaluating dependent foo/1.0.0 results in {foo^ | libfoo->{foo/1,1}}
             trace: collect_build_prerequisites: re-evaluated foo/1.0.0
             trace: collect_build_prerequisites: reeval fox/1.0.0
-            %.*
             trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
             trace: postponed_configurations::add: add {fox^ 1,1: libfoo} to {foo^ | libfoo->{foo/1,1}}
             trace: collect_build_prerequisites: re-evaluating dependent fox/1.0.0 results in {foo^ fox^ | libfoo->{foo/1,1 fox/1,1}}
             trace: collect_build_prerequisites: re-evaluated fox/1.0.0
             trace: collect_build_postponed (1): cfg-negotiate begin {foo^ fox^ | libfoo->{foo/1,1 fox/1,1}}
-            %.*
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libfoo/1.0.0
             trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -6623,34 +6582,16 @@ test.arguments += --sys-no-query
             trace: collect_build_postponed (1): cfg-negotiate end {foo^ fox^ | libfoo->{foo/1,1 fox/1,1}}!
             trace: collect_build_postponed (1): end {foo^ | libfoo->{foo/1,1}}
             trace: collect_build_postponed (0): end
-            %.*
             trace: execute_plan: simulate: yes
             %.*
             build plan:
               upgrade libfoo/1.0.0
                 config.libfoo.extras=true (set by foo)
               reconfigure fox/1.0.0 (dependent of libfoo)
+                config.fox.libfoo_extras=true (set by fox)
               reconfigure foo/1.0.0 (dependent of libfoo)
-            %.*
-            disfigured foo/1.0.0
-            %.*
-            disfigured fox/1.0.0
-            %.*
-            disfigured libfoo/0.1.0
-            %.*
-            fetched libfoo/1.0.0
-            %.*
-            unpacked libfoo/1.0.0
-            %.*
-            configured libfoo/1.0.0
-            %.*
-            configured foo/1.0.0
-            %.*
-            updated libfoo/1.0.0
-            %.*
-            updated fox/1.0.0
-            %.*
-            updated foo/1.0.0
+                config.foo.libfoo_extras=true (set by foo)
+            trace: execute_plan: simulate: no
             %.*
             EOE
 
@@ -6691,54 +6632,43 @@ test.arguments += --sys-no-query
                 libfoo configured 1.0.0
             EOO
 
-          $* fix/0.1.0 libbiz biz/0.1.0 2>>~%EOE%;
+          $* fix/0.1.0 libbiz biz/0.1.0 2>&1 | $filter 2>>~%EOE%;
             %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add fix/0.1.0
             trace: collect_build: add libbiz/1.0.0
             trace: collect_build: add biz/0.1.0
             trace: collect_build_prerequisites: begin fix/0.1.0
-            %.*
             trace: collect_build: add foo/0.1.0
             info: package fix dependency on (foo == 0.1.0) is forcing downgrade of foo/1.0.0 to 0.1.0
             trace: collect_build_prerequisites: no cfg-clause for dependency foo/0.1.0 of dependent fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval bus/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated bus/0.1.0: 1,1
             trace: collect_build_prerequisites: cfg-postpone dependency foo/0.1.0 of existing dependent bus/0.1.0 due to dependency foo/0.1.0
             trace: collect_build: add bus/0.1.0
             trace: postponed_configurations::add: create {bus^ | foo->{bus/1,1}}
             trace: collect_build_prerequisites: end fix/0.1.0
             trace: collect_build_prerequisites: begin libbiz/1.0.0
-            %.*
             trace: collect_build: add libbar/1.0.0
             trace: collect_build_prerequisites: no cfg-clause for dependency libbar/1.0.0 of dependent libbiz/1.0.0
             trace: collect_build_prerequisites: begin libbar/1.0.0
             trace: collect_build_prerequisites: end libbar/1.0.0
             trace: collect_build_prerequisites: end libbiz/1.0.0
             trace: collect_build_prerequisites: begin biz/0.1.0
-            %.*
             trace: collect_build: pick libbiz/0.1.0 over libbiz/1.0.0
             trace: collect_build: libbiz/1.0.0 package version needs to be replaced with libbiz/0.1.0
             trace: pkg_build: collection failed due to package version replacement, retry from scratch
-            %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add fix/0.1.0
             trace: collect_build: apply version replacement for libbiz/1.0.0
             trace: collect_build: replacement: libbiz/0.1.0
             trace: collect_build: add libbiz/0.1.0
             trace: collect_build: add biz/0.1.0
             trace: collect_build_prerequisites: begin fix/0.1.0
-            %.*
             trace: collect_build: add foo/0.1.0
             info: package fix dependency on (foo == 0.1.0) is forcing downgrade of foo/1.0.0 to 0.1.0
             trace: collect_build_prerequisites: no cfg-clause for dependency foo/0.1.0 of dependent fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval bus/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated bus/0.1.0: 1,1
             trace: collect_build_prerequisites: cfg-postpone dependency foo/0.1.0 of existing dependent bus/0.1.0 due to dependency foo/0.1.0
             trace: collect_build: add bus/0.1.0
@@ -6747,27 +6677,21 @@ test.arguments += --sys-no-query
             trace: collect_build_prerequisites: begin libbiz/0.1.0
             trace: collect_build_prerequisites: end libbiz/0.1.0
             trace: collect_build_prerequisites: begin biz/0.1.0
-            %.*
             trace: collect_build_prerequisites: no cfg-clause for dependency libbiz/0.1.0 of dependent biz/0.1.0
             trace: collect_build_prerequisites: end biz/0.1.0
             trace: collect_build_postponed (0): begin
             trace: collect_build_postponed (1): begin {bus^ | foo->{bus/1,1}}
-            %.*
             trace: collect_build_prerequisites: pre-reeval bus/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated bus/0.1.0: 1,1
             trace: collect_build_postponed (1): re-evaluate existing dependents for {bus^ | foo->{bus/1,1}}
             trace: collect_build_prerequisites: reeval bus/0.1.0
-            %.*
             trace: collect_build: pick foo/0.1.0 over foo/1.0.0
             trace: postponed_configurations::add: add {bus^ 1,1: foo} to {bus^ | foo->{bus/1,1}}
             trace: collect_build_prerequisites: re-evaluating dependent bus/0.1.0 results in {bus^ | foo->{bus/1,1}}
             trace: collect_build_prerequisites: re-evaluated bus/0.1.0
             trace: collect_build_postponed (1): cfg-negotiate begin {bus^ | foo->{bus/1,1}}
-            %.*
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin foo/0.1.0
-            %.*
             trace: collect_build: add libfoo/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/0.1.0
             trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
@@ -6778,10 +6702,8 @@ test.arguments += --sys-no-query
             trace: collect_build_prerequisites: end bus/0.1.0
             trace: collect_build_postponed (1): cfg-negotiate end {bus^ | foo->{bus/1,1}}!
             trace: collect_build_postponed (2): begin {foo | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_postponed (2): skip being built existing dependent foo of dependency libfoo
             trace: collect_build_postponed (2): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: skip configured libfoo/1.0.0
             trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
@@ -6792,13 +6714,13 @@ test.arguments += --sys-no-query
             trace: collect_build_postponed (2): end {foo | libfoo->{foo/1,1}}
             trace: collect_build_postponed (1): end {bus^ | foo->{bus/1,1}}
             trace: collect_build_postponed (0): end
-            %.*
             trace: execute_plan: simulate: yes
             %.*
             build plan:
               downgrade foo/0.1.0 (required by bus, fix)
                 config.foo.extras=true (set by bus)
               reconfigure bus/0.1.0 (dependent of foo)
+                config.bus.foo_extras=true (set by bus)
               new fix/0.1.0
               new libbiz/0.1.0
               new biz/0.1.0
@@ -6836,67 +6758,55 @@ test.arguments += --sys-no-query
           #
           $* fix --verbose 1 2>!;
 
-          $* libfoo/0.1.0 fix/0.1.0 2>>~%EOE%;
+          $pkg_status -r >>EOO;
+            !fix configured 1.0.0
+              foo configured 1.0.0
+                libfoo configured 1.0.0
+            EOO
+
+          $* libfoo/0.1.0 fix/0.1.0 2>&1 | $filter 2>>~%EOE%;
             %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval foo/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated foo/1.0.0: 1,1
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/0.1.0 of existing dependent foo/1.0.0 due to dependency libfoo/0.1.0
             trace: collect_build: add foo/1.0.0
             trace: postponed_configurations::add: create {foo^ | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_prerequisites: begin fix/0.1.0
-            %.*
             trace: collect_build: pick foo/0.1.0 over foo/1.0.0
             trace: collect_build: foo/1.0.0 package version needs to be replaced with foo/0.1.0
             trace: pkg_build: collection failed due to package version replacement, retry from scratch
-            %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: skip expected to be built existing dependent foo of dependency libfoo
             trace: collect_build_prerequisites: begin libfoo/0.1.0
             trace: collect_build_prerequisites: end libfoo/0.1.0
-            %.*
             trace: collect_build_prerequisites: begin fix/0.1.0
-            %.*
             trace: collect_build: apply version replacement for foo/0.1.0
             trace: collect_build: replacement: foo/0.1.0
             trace: collect_build: add foo/0.1.0
             info: package fix dependency on (foo == 0.1.0) is forcing downgrade of foo/1.0.0 to 0.1.0
             trace: collect_build_prerequisites: no cfg-clause for dependency foo/0.1.0 of dependent fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: skip being built existing dependent fix of dependency foo
             trace: collect_build_prerequisites: begin foo/0.1.0
-            %.*
             trace: collect_build: pick libfoo/0.1.0 over libfoo/1.0.0
             trace: collect_build_prerequisites: cannot cfg-postpone dependency libfoo/0.1.0 of dependent foo/0.1.0 (collected prematurely), throwing postpone_dependency
             trace: pkg_build: collection failed due to prematurely collected dependency (libfoo), retry from scratch
-            %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add fix/0.1.0
             trace: pkg_build: dep-postpone user-specified libfoo
-            %.*
             trace: collect_build_prerequisites: begin fix/0.1.0
-            %.*
             trace: collect_build: apply version replacement for foo/0.1.0
             trace: collect_build: replacement: foo/0.1.0
             trace: collect_build: add foo/0.1.0
             info: package fix dependency on (foo == 0.1.0) is forcing downgrade of foo/1.0.0 to 0.1.0
             trace: collect_build_prerequisites: no cfg-clause for dependency foo/0.1.0 of dependent fix/0.1.0
-            %.*
             trace: collect_build_prerequisites: skip being built existing dependent fix of dependency foo
             trace: collect_build_prerequisites: begin foo/0.1.0
-            %.*
             trace: collect_build: pick libfoo/0.1.0 over libfoo/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/0.1.0 of dependent foo/0.1.0
             trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
@@ -6904,10 +6814,8 @@ test.arguments += --sys-no-query
             trace: collect_build_prerequisites: end fix/0.1.0
             trace: collect_build_postponed (0): begin
             trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_postponed (1): skip being built existing dependent foo of dependency libfoo
             trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
-            %.*
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libfoo/0.1.0
             trace: collect_build_prerequisites: end libfoo/0.1.0
@@ -6918,7 +6826,6 @@ test.arguments += --sys-no-query
             trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
             trace: collect_build_postponed (1): end {foo | libfoo->{foo/1,1}}
             trace: collect_build_postponed (0): end
-            %.*
             trace: execute_plan: simulate: yes
             %.*
             build plan:
@@ -6958,15 +6865,18 @@ test.arguments += --sys-no-query
           #
           $* tex --verbose 1 2>!;
 
-          $* libfoo/0.1.0 libbar/0.1.0 2>>~%EOE%;
+          $pkg_status -r >>EOO;
+            !tex configured 1.0.0
+              libbar configured 1.0.0
+              libfoo configured 1.0.0
+            EOO
+
+          $* libfoo/0.1.0 libbar/0.1.0 2>&1 | $filter 2>>~%EOE%;
             %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add libbar/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
             trace: collect_build: pick libbar/0.1.0 over libbar/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libbar/0.1.0 of existing dependent tex/1.0.0 due to dependency libfoo/0.1.0
@@ -6975,36 +6885,29 @@ test.arguments += --sys-no-query
             trace: pkg_build: dep-postpone user-specified libbar since already in cluster {tex^ | libbar->{tex/1,1}}
             trace: collect_build_postponed (0): begin
             trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-            %.*
             trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
             trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: reeval tex/1.0.0
-            %.*
             trace: collect_build: pick libbar/0.1.0 over libbar/1.0.0
             trace: postponed_configurations::add: add {tex^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: re-evaluating dependent tex/1.0.0 results in {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: re-evaluated tex/1.0.0
             trace: collect_build_postponed (1): cfg-negotiate begin {tex^ | libbar->{tex/1,1}}
-            %.*
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libbar/0.1.0
             trace: collect_build_prerequisites: end libbar/0.1.0
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
             trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent tex/1.0.0
             trace: collect_build_prerequisites: resume tex/1.0.0
-            %.*
             trace: collect_build: pick libfoo/0.1.0 over libfoo/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/0.1.0 of dependent tex/1.0.0
             trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
             trace: collect_build_prerequisites: postpone tex/1.0.0
             trace: collect_build_postponed (1): cfg-negotiate end {tex^ | libbar->{tex/1,1}}!
             trace: collect_build_postponed (2): begin {tex | libfoo->{tex/2,1}}
-            %.*
             trace: collect_build_postponed (2): skip being built existing dependent tex of dependency libfoo
             trace: collect_build_postponed (2): cfg-negotiate begin {tex | libfoo->{tex/2,1}}
-            %.*
             trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libfoo/0.1.0
             trace: collect_build_prerequisites: end libfoo/0.1.0
@@ -7016,7 +6919,6 @@ test.arguments += --sys-no-query
             trace: collect_build_postponed (2): end {tex | libfoo->{tex/2,1}}
             trace: collect_build_postponed (1): end {tex^ | libbar->{tex/1,1}}
             trace: collect_build_postponed (0): end
-            %.*
             trace: execute_plan: simulate: yes
             %.*
             build plan:
@@ -7025,6 +6927,7 @@ test.arguments += --sys-no-query
               downgrade libbar/0.1.0
                 config.libbar.extras=true (set by tex)
               reconfigure tex/1.0.0 (dependent of libbar, libfoo)
+                config.tex.libfoo_extras=true (set by tex)
             trace: execute_plan: simulate: no
             %.*
             EOE
@@ -7054,33 +6957,31 @@ test.arguments += --sys-no-query
           #
           $* tex --verbose 1 2>!;
 
-          $* libfoo/0.1.0 bar/0.1.0 2>>~%EOE%;
+          $pkg_status -r >>EOO;
+            !tex configured 1.0.0
+              libbar configured 1.0.0
+              libfoo configured 1.0.0
+            EOO
+
+          $* libfoo/0.1.0 bar/0.1.0 2>&1 | $filter 2>>~%EOE%;
             %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add bar/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
             trace: collect_build: add libbar/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libfoo/0.1.0
             trace: collect_build: add tex/1.0.0
             trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: begin bar/0.1.0
-            %.*
             trace: collect_build: pick libbar/0.1.0 over libbar/1.0.0
             trace: collect_build: libbar/1.0.0 package version needs to be replaced with libbar/0.1.0
             trace: pkg_build: collection failed due to package version replacement, retry from scratch
-            %.*
             trace: pkg_build: refine package collection/plan execution from scratch
-            %.*
             trace: collect_build: add libfoo/0.1.0
             trace: collect_build: add bar/0.1.0
-            %.*
             trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
             trace: collect_build: apply version replacement for libbar/1.0.0
             trace: collect_build: replacement: libbar/0.1.0
@@ -7089,25 +6990,20 @@ test.arguments += --sys-no-query
             trace: collect_build: add tex/1.0.0
             trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: begin bar/0.1.0
-            %.*
             trace: collect_build_prerequisites: cfg-postpone dependency libbar/0.1.0 of dependent bar/0.1.0
             trace: postponed_configurations::add: add {bar 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
             trace: collect_build_prerequisites: postpone bar/0.1.0
             trace: collect_build_postponed (0): begin
             trace: collect_build_postponed (1): begin {bar tex^ | libbar->{bar/1,1 tex/1,1}}
-            %.*
             trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-            %.*
             trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
             trace: collect_build_postponed (1): re-evaluate existing dependents for {bar tex^ | libbar->{bar/1,1 tex/1,1}}
             trace: collect_build_prerequisites: reeval tex/1.0.0
-            %.*
             trace: collect_build: pick libbar/0.1.0 over libbar/1.0.0
             trace: postponed_configurations::add: add {tex^ 1,1: libbar} to {bar tex^ | libbar->{bar/1,1 tex/1,1}}
             trace: collect_build_prerequisites: re-evaluating dependent tex/1.0.0 results in {bar tex^ | libbar->{bar/1,1 tex/1,1}}
             trace: collect_build_prerequisites: re-evaluated tex/1.0.0
             trace: collect_build_postponed (1): cfg-negotiate begin {bar tex^ | libbar->{bar/1,1 tex/1,1}}
-            %.*
             trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libbar/0.1.0
             trace: collect_build_prerequisites: end libbar/0.1.0
@@ -7117,17 +7013,14 @@ test.arguments += --sys-no-query
             trace: collect_build_prerequisites: end bar/0.1.0
             trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent tex/1.0.0
             trace: collect_build_prerequisites: resume tex/1.0.0
-            %.*
             trace: collect_build: pick libfoo/0.1.0 over libfoo/1.0.0
             trace: collect_build_prerequisites: cfg-postpone dependency libfoo/0.1.0 of dependent tex/1.0.0
             trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
             trace: collect_build_prerequisites: postpone tex/1.0.0
             trace: collect_build_postponed (1): cfg-negotiate end {bar tex^ | libbar->{bar/1,1 tex/1,1}}!
             trace: collect_build_postponed (2): begin {tex | libfoo->{tex/2,1}}
-            %.*
             trace: collect_build_postponed (2): skip being built existing dependent tex of dependency libfoo
             trace: collect_build_postponed (2): cfg-negotiate begin {tex | libfoo->{tex/2,1}}
-            %.*
             trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
             trace: collect_build_prerequisites: begin libfoo/0.1.0
             trace: collect_build_prerequisites: end libfoo/0.1.0
@@ -7139,7 +7032,6 @@ test.arguments += --sys-no-query
             trace: collect_build_postponed (2): end {tex | libfoo->{tex/2,1}}
             trace: collect_build_postponed (1): end {bar tex^ | libbar->{bar/1,1 tex/1,1}}
             trace: collect_build_postponed (0): end
-            %.*
             trace: execute_plan: simulate: yes
             %.*
             build plan:
@@ -7148,6 +7040,7 @@ test.arguments += --sys-no-query
               downgrade libbar/0.1.0 (required by bar, tex)
                 config.libbar.extras=true (set by bar)
               reconfigure tex/1.0.0 (dependent of libbar, libfoo)
+                config.tex.libfoo_extras=true (set by tex)
               new bar/0.1.0
             trace: execute_plan: simulate: no
             %.*
@@ -7265,14 +7158,11 @@ test.arguments += --sys-no-query
             #
             $* bax baz --verbose 1 2>!;
 
-            $* libbox/0.1.0 2>>~%EOE%;
+            $* libbox/0.1.0 2>&1 | $filter 2>>~%EOE%;
               %.*
               trace: pkg_build: refine package collection/plan execution from scratch
-              %.*
               trace: collect_build: add libbox/0.1.0
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build: add libfoo/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of existing dependent bax/1.0.0 due to dependency libbox/0.1.0
@@ -7280,70 +7170,53 @@ test.arguments += --sys-no-query
               trace: postponed_configurations::add: create {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_postponed (0): begin
               trace: collect_build_postponed (1): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
-              %.*
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
               trace: collect_build: add baz/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (1): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (1): cfg-negotiate begin {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
-              %.*
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
               trace: collect_build_prerequisites: skip configured libfoo/1.0.0
               trace: collect_build_prerequisites: skip configured libbar/1.0.0
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
               trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}?
-              %.*
               trace: collect_build_prerequisites: skip being built existing dependent bax of dependency libbox
-              %.*
               trace: collect_build_prerequisites: cfg-postponing dependent bax/1.0.0 involves (being) negotiated configurations and results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{bax/2,1 baz/1,1} libbox->{bax/2,1}}?, throwing retry_configuration
               trace: collect_build_postponed (0): cfg-negotiation of {bax^ | libfoo->{bax/1,1}} failed due to dependent bax, refining configuration
               trace: collect_build_postponed (1): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
               trace: collect_build: add baz/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (1): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (1): cfg-negotiate begin {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
@@ -7353,12 +7226,10 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
               trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}?
-              %.*
               trace: collect_build_prerequisites: skip being built existing dependent bax of dependency libbox
               trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bax/1.0.0 is negotiated
               trace: collect_build_prerequisites: collecting cfg-postponed dependency libbox/0.1.0 of dependent bax/1.0.0
@@ -7372,13 +7243,13 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): cfg-negotiate end {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{bax/2,1 baz/1,1} libbox->{bax/2,1}}!
               trace: collect_build_postponed (1): end {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_postponed (0): end
-              %.*
               trace: execute_plan: simulate: yes
               %.*
               build plan:
                 downgrade libbox/0.1.0
                   config.libbox.extras=true (set by bax)
                 reconfigure bax/1.0.0 (dependent of libbox, libfoo)
+                  config.bax.libfoo_extras=true (set by bax)
               trace: execute_plan: simulate: no
               %.*
               EOE
@@ -7413,13 +7284,11 @@ test.arguments += --sys-no-query
             #
             $* bax baz --verbose 1 2>!;
 
-            $* box/0.1.0 2>>~%EOE%;
+            $* box/0.1.0 2>&1 | $filter 2>>~%EOE%;
               %.*
               trace: pkg_build: refine package collection/plan execution from scratch
-              %.*
               trace: collect_build: add box/0.1.0
               trace: collect_build_prerequisites: begin box/0.1.0
-              %.*
               trace: collect_build: add libbox/0.1.0
               info: package box dependency on (libbox == 0.1.0) is forcing downgrade of libbox/1.0.0 to 0.1.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent box/0.1.0
@@ -7427,20 +7296,16 @@ test.arguments += --sys-no-query
               trace: collect_build_prerequisites: postpone box/0.1.0
               trace: collect_build_postponed (0): begin
               trace: collect_build_postponed (1): begin {box | libbox->{box/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build: add libfoo/1.0.0
               trace: collect_build_postponed (1): re-evaluate existing dependents for {box | libbox->{box/1,1}}
               trace: collect_build: add bax/1.0.0
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: create {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
               trace: collect_build_postponed (1): cfg-negotiate begin {box | libbox->{box/1,1}}
-              %.*
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
               trace: collect_build_prerequisites: begin libbox/0.1.0
               trace: collect_build_prerequisites: end libbox/0.1.0
@@ -7450,32 +7315,25 @@ test.arguments += --sys-no-query
               trace: collect_build_prerequisites: end box/0.1.0
               trace: collect_build_postponed (1): cfg-negotiate end {box | libbox->{box/1,1}}!
               trace: collect_build_postponed (2): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_postponed (2): skip being built existing dependent bax of dependency libfoo
-              %.*
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (2): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build: add baz/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (2): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (2): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (2): cfg-negotiate begin {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
-              %.*
               trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
               trace: collect_build_prerequisites: skip configured libfoo/1.0.0
               trace: collect_build_prerequisites: skip configured libbar/1.0.0
               trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
@@ -7484,32 +7342,25 @@ test.arguments += --sys-no-query
               trace: collect_build_prerequisites: cfg-postponing dependent bax/1.0.0 merges non-negotiated and/or being negotiated configurations in and results in {bax baz^ box | libbox->{bax/2,1 box/1,1} libbar->{bax/2,1 baz/1,1} libfoo->{bax/1,1 baz/1,1}}!, throwing merge_configuration
               trace: collect_build_postponed (0): cfg-negotiation of {box | libbox->{box/1,1}} failed due to non-negotiated clusters, force-merging based on shadow cluster {bax baz^ box | libbox->{bax/2,1 box/1,1} libbar->{bax/2,1 baz/1,1} libfoo->{bax/1,1 baz/1,1}}!
               trace: collect_build_postponed (1): begin {box | libbox->{box/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build: add libfoo/1.0.0
               trace: collect_build_postponed (1): re-evaluate existing dependents for {box | libbox->{box/1,1}}
               trace: collect_build: add bax/1.0.0
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {box | libbox->{box/1,1}} (shadow cluster-based)
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ box | libbox->{box/1,1} libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libfoo
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ box | libbox->{box/1,1} libfoo->{bax/1,1}}
               trace: collect_build: add baz/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ box | libbox->{box/1,1} libfoo->{bax/1,1}} (shadow cluster-based)
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ box | libbox->{box/1,1} libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (1): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (1): cfg-negotiate begin {bax^ baz^ box | libbox->{box/1,1} libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
@@ -7521,7 +7372,6 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
@@ -7539,13 +7389,13 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): cfg-negotiate end {bax^ baz^ box | libbox->{bax/2,1 box/1,1} libfoo->{bax/1,1 baz/1,1} libbar->{bax/2,1 baz/1,1}}!
               trace: collect_build_postponed (1): end {box | libbox->{box/1,1}}
               trace: collect_build_postponed (0): end
-              %.*
               trace: execute_plan: simulate: yes
               %.*
               build plan:
                 downgrade libbox/0.1.0 (required by bax, box)
                   config.libbox.extras=true (set by box)
                 reconfigure bax/1.0.0 (dependent of libbox)
+                  config.bax.libfoo_extras=true (set by bax)
                 new box/0.1.0
               trace: execute_plan: simulate: no
               %.*
@@ -7590,14 +7440,11 @@ test.arguments += --sys-no-query
                 libfoo configured 1.0.0
               EOO
 
-            $* libbox/0.1.0 ?baz 2>>~%EOE%;
+            $* libbox/0.1.0 ?baz 2>&1 | $filter 2>>~%EOE%;
               %.*
               trace: pkg_build: refine package collection/plan execution from scratch
-              %.*
               trace: collect_build: add libbox/0.1.0
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build: add libfoo/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of existing dependent bax/1.0.0 due to dependency libbox/0.1.0
@@ -7605,67 +7452,51 @@ test.arguments += --sys-no-query
               trace: postponed_configurations::add: create {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_postponed (0): begin
               trace: collect_build_postponed (1): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (1): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (1): cfg-negotiate begin {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
-              %.*
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
               trace: collect_build_prerequisites: skip configured libfoo/1.0.0
               trace: collect_build_prerequisites: skip configured libbar/1.0.0
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
               trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}?
-              %.*
               trace: collect_build_prerequisites: skip being built existing dependent bax of dependency libbox
-              %.*
               trace: collect_build_prerequisites: cfg-postponing dependent bax/1.0.0 involves (being) negotiated configurations and results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{bax/2,1 baz/1,1} libbox->{bax/2,1}}?, throwing retry_configuration
               trace: collect_build_postponed (0): cfg-negotiation of {bax^ | libfoo->{bax/1,1}} failed due to dependent bax, refining configuration
               trace: collect_build_postponed (1): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build_prerequisites: pre-reeval baz/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated baz/1.0.0: 1,1
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
               trace: collect_build_prerequisites: reeval baz/1.0.0
-              %.*
               trace: collect_build: add libbar/1.0.0
               trace: postponed_configurations::add: add {baz^ 1,1: libbar libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent baz/1.0.0 results in {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
               trace: collect_build_prerequisites: re-evaluated baz/1.0.0
-              %.*
               trace: collect_build_postponed (1): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (1): skip being built existing dependent baz of dependency libbar
               trace: collect_build_postponed (1): cfg-negotiate begin {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}
@@ -7675,12 +7506,10 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
               trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{baz/1,1}}?
-              %.*
               trace: collect_build_prerequisites: skip being built existing dependent bax of dependency libbox
               trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bax/1.0.0 is negotiated
               trace: collect_build_prerequisites: collecting cfg-postponed dependency libbox/0.1.0 of dependent bax/1.0.0
@@ -7694,17 +7523,12 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): cfg-negotiate end {bax^ baz^ | libfoo->{bax/1,1 baz/1,1} libbar->{bax/2,1 baz/1,1} libbox->{bax/2,1}}!
               trace: collect_build_postponed (1): end {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_postponed (0): end
-              %.*
               trace: execute_plan: simulate: yes
               %.*
               trace: evaluate_dependency: baz/1.0.0: unused
-              %.*
               trace: pkg_build: refine package collection/plan execution from scratch
-              %.*
               trace: collect_build: add libbox/0.1.0
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build: add libfoo/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of existing dependent bax/1.0.0 due to dependency libbox/0.1.0
@@ -7713,14 +7537,11 @@ test.arguments += --sys-no-query
               trace: collect_drop: overwrite baz
               trace: collect_build_postponed (0): begin
               trace: collect_build_postponed (1): begin {bax^ | libfoo->{bax/1,1}}
-              %.*
               trace: collect_build_prerequisites: pre-reeval bax/1.0.0
-              %.*
               trace: collect_build_prerequisites: pre-reevaluated bax/1.0.0: 1,1
               trace: collect_build_postponed (1): skip being dropped existing dependent baz of dependency libfoo
               trace: collect_build_postponed (1): re-evaluate existing dependents for {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: reeval bax/1.0.0
-              %.*
               trace: postponed_configurations::add: add {bax^ 1,1: libfoo} to {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluating dependent bax/1.0.0 results in {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_prerequisites: re-evaluated bax/1.0.0
@@ -7730,7 +7551,6 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
               trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bax/1.0.0
               trace: collect_build_prerequisites: resume bax/1.0.0
-              %.*
               trace: collect_build: pick libbox/0.1.0 over libbox/1.0.0
               trace: collect_build_prerequisites: cfg-postpone dependency libbox/0.1.0 of dependent bax/1.0.0
               trace: collect_build: add libbar/1.0.0
@@ -7739,9 +7559,7 @@ test.arguments += --sys-no-query
               trace: collect_build_prerequisites: postpone bax/1.0.0
               trace: collect_build_postponed (1): cfg-negotiate end {bax^ | libfoo->{bax/1,1}}!
               trace: collect_build_postponed (2): begin {bax | libbox->{bax/2,1} libbar->{bax/2,1}}
-              %.*
               trace: collect_build_postponed (2): skip being built existing dependent bax of dependency libbox
-              %.*
               trace: collect_build_postponed (2): skip being built existing dependent bax of dependency libbar
               trace: collect_build_postponed (2): skip being dropped existing dependent baz of dependency libbar
               trace: collect_build_postponed (2): cfg-negotiate begin {bax | libbox->{bax/2,1} libbar->{bax/2,1}}
@@ -7757,13 +7575,13 @@ test.arguments += --sys-no-query
               trace: collect_build_postponed (2): end {bax | libbox->{bax/2,1} libbar->{bax/2,1}}
               trace: collect_build_postponed (1): end {bax^ | libfoo->{bax/1,1}}
               trace: collect_build_postponed (0): end
-              %.*
               trace: execute_plan: simulate: yes
               %.*
               build plan:
                 downgrade libbox/0.1.0
                   config.libbox.extras=true (set by bax)
                 reconfigure bax/1.0.0 (dependent of libbox, libfoo)
+                  config.bax.libfoo_extras=true (set by bax)
                 drop baz/1.0.0 (unused)
               trace: execute_plan: simulate: no
               %.*
@@ -8259,55 +8077,46 @@ test.arguments += --sys-no-query
         #
         #  foo: depends: libfoo(c)
         #
-        $* bas bax bix buz buc 2>>~%EOE%;
+        $* bas bax bix buz buc 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add bas/1.0.0
           trace: collect_build: add bax/1.0.0
           trace: collect_build: add bix/1.0.0
           trace: collect_build: add buz/1.0.0
           trace: collect_build: add buc/1.0.0
           trace: collect_build_prerequisites: begin bas/1.0.0
-          %.*
           trace: collect_build: add libbar/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bas/1.0.0
           trace: postponed_configurations::add: create {bas | libbar->{bas/1,1}}
           trace: collect_build_prerequisites: postpone bas/1.0.0
           trace: collect_build_prerequisites: begin bax/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent bax/1.0.0
           trace: postponed_configurations::add: create {bax | libfoo->{bax/1,1}}
           trace: collect_build_prerequisites: postpone bax/1.0.0
           trace: collect_build_prerequisites: begin bix/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bix/1.0.0
           trace: collect_build: add bar/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency bar/1.0.0 of dependent bix/1.0.0
           trace: postponed_configurations::add: add {bix 1,1: libbar bar} to {bas | libbar->{bas/1,1}}
           trace: collect_build_prerequisites: postpone bix/1.0.0
           trace: collect_build_prerequisites: begin buz/1.0.0
-          %.*
           trace: collect_build: add bux/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency bux/1.0.0 of dependent buz/1.0.0
           trace: postponed_configurations::add: create {buz | bux->{buz/1,1}}
           trace: collect_build_prerequisites: postpone buz/1.0.0
           trace: collect_build_prerequisites: begin buc/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent buc/1.0.0
           trace: postponed_configurations::add: add {buc 1,1: libfoo} to {bax | libfoo->{bax/1,1}}
           trace: collect_build_prerequisites: postpone buc/1.0.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libbar/1.0.0
           trace: collect_build_prerequisites: end libbar/1.0.0
           trace: collect_build_prerequisites: begin bar/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bar/1.0.0
           trace: postponed_configurations::add: add {bar 1,1: libbar} to {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}?
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bar/1.0.0 is negotiated
@@ -8316,43 +8125,35 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
           trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bas/1.0.0
           trace: collect_build_prerequisites: resume bas/1.0.0
-          %.*
           trace: collect_build: add bus/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency bus/1.0.0 of dependent bas/1.0.0
           trace: postponed_configurations::add: create {bas | bus->{bas/2,1}}
           trace: collect_build_prerequisites: postpone bas/1.0.0
           trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bix/1.0.0
           trace: collect_build_prerequisites: resume bix/1.0.0
-          %.*
           trace: collect_build_prerequisites: dep-postpone dependency bux/1.0.0 of dependent bix/1.0.0 since already in cluster {buz | bux->{buz/1,1}}
           trace: collect_build_prerequisites: end bix/1.0.0
           trace: collect_build_postponed (1): cfg-negotiate end {bar bas bix | libbar->{bar/1,1 bas/1,1 bix/1,1} bar->{bix/1,1}}!
           trace: collect_build_postponed (2): begin {bax buc | libfoo->{bax/1,1 buc/1,1}}
-          %.*
           trace: collect_build_postponed (2): cfg-negotiate begin {bax buc | libfoo->{bax/1,1 buc/1,1}}
-          %.*
           trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
           trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
           trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent bax/1.0.0
           trace: collect_build_prerequisites: resume bax/1.0.0
-          %.*
           trace: collect_build: add libbox/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbox/1.0.0 of dependent bax/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
           trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bar bas bix | libbar->{bar/1,1 bas/1,1 bix/1,1} bar->{bix/1,1}}!
-          %.*
           trace: collect_build_prerequisites: cfg-postponing dependent bax/1.0.0 involves (being) negotiated configurations and results in {bar bas bax bix | libbar->{bar/1,1 bas/1,1 bax/2,1 bix/1,1} bar->{bix/1,1} libbox->{bax/2,1}}!, throwing retry_configuration
           trace: collect_build_postponed (0): cfg-negotiation of {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}} failed due to dependent bax, refining configuration
           trace: collect_build_postponed (1): begin {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libbar/1.0.0
           trace: collect_build_prerequisites: end libbar/1.0.0
           trace: collect_build_prerequisites: begin bar/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bar/1.0.0
           trace: postponed_configurations::add: add {bar 1,1: libbar} to {bas bix | libbar->{bas/1,1 bix/1,1} bar->{bix/1,1}}?
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bar/1.0.0 is negotiated
@@ -8361,19 +8162,16 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
           trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bas/1.0.0
           trace: collect_build_prerequisites: resume bas/1.0.0
-          %.*
           trace: collect_build: add bus/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency bus/1.0.0 of dependent bas/1.0.0
           trace: postponed_configurations::add: create {bas | bus->{bas/2,1}}
           trace: collect_build_prerequisites: postpone bas/1.0.0
           trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent bix/1.0.0
           trace: collect_build_prerequisites: resume bix/1.0.0
-          %.*
           trace: collect_build_prerequisites: dep-postpone dependency bux/1.0.0 of dependent bix/1.0.0 since already in cluster {buz | bux->{buz/1,1}}
           trace: collect_build_prerequisites: end bix/1.0.0
           trace: collect_build_postponed (1): cfg-negotiate end {bar bas bix | libbar->{bar/1,1 bas/1,1 bix/1,1} bar->{bix/1,1}}!
           trace: collect_build_postponed (2): begin {bax buc | libfoo->{bax/1,1 buc/1,1}}
-          %.*
           trace: collect_build_postponed (2): cfg-negotiate begin {bax buc | libfoo->{bax/1,1 buc/1,1}}
           trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
@@ -8381,12 +8179,10 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
           trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent bax/1.0.0
           trace: collect_build_prerequisites: resume bax/1.0.0
-          %.*
           trace: collect_build: add libbox/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbox/1.0.0 of dependent bax/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bax/1.0.0
           trace: postponed_configurations::add: add {bax 2,1: libbox libbar} to {bar bas bix | libbar->{bar/1,1 bas/1,1 bix/1,1} bar->{bix/1,1}}!
-          %.*
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bax/1.0.0 is negotiated
           trace: collect_build_prerequisites: collecting cfg-postponed dependency libbox/1.0.0 of dependent bax/1.0.0
           trace: collect_build_prerequisites: begin libbox/1.0.0
@@ -8395,18 +8191,14 @@ test.arguments += --sys-no-query
           trace: collect_build_prerequisites: end bax/1.0.0
           trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent buc/1.0.0
           trace: collect_build_prerequisites: resume buc/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency bux/1.0.0 of dependent buc/1.0.0
           trace: postponed_configurations::add: add {buc 2,1: bux} to {buz | bux->{buz/1,1}}
           trace: collect_build_prerequisites: postpone buc/1.0.0
           trace: collect_build_postponed (2): cfg-negotiate end {bax buc | libfoo->{bax/1,1 buc/1,1}}!
           trace: collect_build_postponed (3): begin {buc buz | bux->{buc/2,1 buz/1,1}}
-          %.*
           trace: collect_build_postponed (3): cfg-negotiate begin {buc buz | bux->{buc/2,1 buz/1,1}}
-          %.*
           trace: collect_build_postponed (3): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin bux/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent bux/1.0.0
           trace: postponed_configurations::add: add {bux 1,1: libbar} to {bar bas bax bix | libbar->{bar/1,1 bas/1,1 bax/2,1 bix/1,1} bar->{bix/1,1} libbox->{bax/2,1}}!
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent bux/1.0.0 is negotiated
@@ -8421,12 +8213,9 @@ test.arguments += --sys-no-query
           trace: collect_build_prerequisites: end buz/1.0.0
           trace: collect_build_postponed (3): cfg-negotiate end {buc buz | bux->{buc/2,1 buz/1,1}}!
           trace: collect_build_postponed (4): begin {bas | bus->{bas/2,1}}
-          %.*
           trace: collect_build_postponed (4): cfg-negotiate begin {bas | bus->{bas/2,1}}
-          %.*
           trace: collect_build_postponed (4): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin bus/1.0.0
-          %.*
           trace: collect_build: add libbaz/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libbaz/1.0.0 of dependent bus/1.0.0
           trace: postponed_configurations::add: create {bus | libbaz->{bus/1,1}}
@@ -8437,28 +8226,22 @@ test.arguments += --sys-no-query
           trace: collect_build_prerequisites: end bas/1.0.0
           trace: collect_build_postponed (4): cfg-negotiate end {bas | bus->{bas/2,1}}!
           trace: collect_build_postponed (5): begin {bus | libbaz->{bus/1,1}}
-          %.*
           trace: collect_build_postponed (5): cfg-negotiate begin {bus | libbaz->{bus/1,1}}
-          %.*
           trace: collect_build_postponed (5): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libbaz/1.0.0
           trace: collect_build_prerequisites: end libbaz/1.0.0
           trace: collect_build_postponed (5): recursively collect cfg-negotiated dependents
           trace: collect_build_postponed (5): select cfg-negotiated dependency alternative for dependent bus/1.0.0
           trace: collect_build_prerequisites: resume bus/1.0.0
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency foo/1.0.0 of dependent bus/1.0.0
           trace: postponed_configurations::add: create {bus | foo->{bus/2,1}}
           trace: collect_build_prerequisites: postpone bus/1.0.0
           trace: collect_build_postponed (5): cfg-negotiate end {bus | libbaz->{bus/1,1}}!
           trace: collect_build_postponed (6): begin {bus | foo->{bus/2,1}}
-          %.*
           trace: collect_build_postponed (6): cfg-negotiate begin {bus | foo->{bus/2,1}}
-          %.*
           trace: collect_build_postponed (6): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: add {foo 1,1: libfoo} to {bax buc | libfoo->{bax/1,1 buc/1,1}}!
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent foo/1.0.0 is negotiated
@@ -8487,12 +8270,14 @@ test.arguments += --sys-no-query
               config.libfoo.extras=true (set by bax)
             new foo/1.0.0 (required by bus)
               config.foo.extras=true (set by bus)
+              config.foo.libfoo_extras=true (set by foo)
             new bus/1.0.0 (required by bas)
               config.bus.extras=true (set by bas)
             new libbar/1.0.0 (required by bar, bas, bax, bix, bux)
               config.libbar.extras=true (set by bas)
             new bas/1.0.0
             new bax/1.0.0
+              config.bax.libfoo_extras=true (set by bax)
             new bar/1.0.0 (required by bix)
               config.bar.extras=true (set by bix)
             new bux/1.0.0 (required by bix, buc, buz)
@@ -12559,20 +12344,17 @@ test.arguments += --sys-no-query
       {
         $clone_cfg;
 
-        $* foo fox/0.1.0 ?libbar 2>>~%EOE%;
+        $* foo fox/0.1.0 ?libbar 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/0.1.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/0.1.0
-          %.*
           trace: collect_build_prerequisites: alt-postpone dependent fox/0.1.0 since max index is reached: 0
             info: dependency alternative: libfoo
           {
@@ -12580,15 +12362,12 @@ test.arguments += --sys-no-query
             {
               config.libfoo.extras = true
             }
-
             accept (false)
           }
           trace: collect_build_prerequisites: postpone fox/0.1.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -12599,34 +12378,26 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
           trace: collect_build_postponed (1): index 1 collect alt-postponed fox/0.1.0
           trace: collect_build_prerequisites: resume fox/0.1.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/0.1.0
-          %.*
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}!
-          %.*
           trace: collect_build_prerequisites: unable to cfg-negotiate dependency alternative 1,1 for dependent fox/0.1.0, throwing unaccept_alternative
           trace: pkg_build: collection failed due to unacceptable alternative, retry from scratch
-          %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/0.1.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/0.1.0
           trace: collect_build_prerequisites: dependency alternative 1,1 for dependent fox/0.1.0 is unacceptable, skipping
-          %.*
           trace: collect_build_prerequisites: no cfg-clause for dependency libbar/1.0.0 of dependent fox/0.1.0
           trace: collect_build_prerequisites: begin libbar/1.0.0
           trace: collect_build_prerequisites: end libbar/1.0.0
           trace: collect_build_prerequisites: end fox/0.1.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
@@ -12648,6 +12419,7 @@ test.arguments += --sys-no-query
             new libfoo/1.0.0 (required by foo)
               config.libfoo.extras=true (set by foo)
             new foo/1.0.0
+              config.foo.libfoo_extras=true (set by foo)
             new libbar/1.0.0 (required by fox)
             new fox/0.1.0
           trace: execute_plan: simulate: no
@@ -12669,20 +12441,17 @@ test.arguments += --sys-no-query
       {
         $clone_cfg;
 
-        $* foo fox/0.2.0 2>>~%EOE%;
+        $* foo fox/0.2.0 2>&1 | $filter 2>>~%EOE%;
           %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/0.2.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/0.2.0
-          %.*
           trace: collect_build_prerequisites: alt-postpone dependent fox/0.2.0 since max index is reached: 0
             info: dependency alternative: libfoo
           {
@@ -12690,15 +12459,12 @@ test.arguments += --sys-no-query
             {
               config.libfoo.extras = false
             }
-
             accept (!$config.libfoo.extras)
           }
           trace: collect_build_prerequisites: postpone fox/0.2.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
           trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -12709,15 +12475,11 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
           trace: collect_build_postponed (1): index 1 collect alt-postponed fox/0.2.0
           trace: collect_build_prerequisites: resume fox/0.2.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/0.2.0
-          %.*
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}!
-          %.*
           trace: collect_build_prerequisites: cfg-postponing dependent fox/0.2.0 involves (being) negotiated configurations and results in {foo fox | libfoo->{foo/1,1 fox/1,1}}!, throwing retry_configuration
           trace: collect_build_postponed (0): cfg-negotiation of {foo | libfoo->{foo/1,1}} failed due to dependent fox, refining configuration
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
@@ -12729,14 +12491,11 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
           trace: collect_build_postponed (1): index 1 collect alt-postponed fox/0.2.0
           trace: collect_build_prerequisites: resume fox/0.2.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/0.2.0
-          %.*
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}!
           trace: collect_build_prerequisites: cfg-postponing dependent fox/0.2.0 involves (being) negotiated configurations and results in {foo fox | libfoo->{foo/1,1 fox/1,1}}!, throwing retry_configuration
           trace: collect_build_postponed (0): cfg-negotiation of {foo | libfoo->{foo/1,1}} failed due to dependent fox, refining configuration
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
@@ -12748,26 +12507,20 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
           trace: collect_build_postponed (1): index 1 collect alt-postponed fox/0.2.0
           trace: collect_build_prerequisites: resume fox/0.2.0
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/0.2.0
-          %.*
           trace: postponed_configurations::add: add {fox 1,1: libfoo} to {foo | libfoo->{foo/1,1}}!
           trace: collect_build_prerequisites: unable to cfg-negotiate dependency alternative 1,1 for dependent fox/0.2.0, throwing unaccept_alternative
           trace: pkg_build: collection failed due to unacceptable alternative, retry from scratch
-          %.*
           trace: pkg_build: refine package collection/plan execution from scratch
-          %.*
           trace: collect_build: add foo/1.0.0
           trace: collect_build: add fox/0.2.0
           trace: collect_build_prerequisites: begin foo/1.0.0
-          %.*
           trace: collect_build: add libfoo/1.0.0
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/1.0.0
           trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
           trace: collect_build_prerequisites: postpone foo/1.0.0
           trace: collect_build_prerequisites: begin fox/0.2.0
           trace: collect_build_prerequisites: dependency alternative 1,1 for dependent fox/0.2.0 is unacceptable, skipping
-          %.*
           trace: collect_build_prerequisites: alt-postpone dependent fox/0.2.0 since max index is reached: 1
             info: dependency alternative: libfoo
           {
@@ -12775,13 +12528,11 @@ test.arguments += --sys-no-query
             {
               config.libfoo.extras = true
             }
-
             accept (true)
           }
           trace: collect_build_prerequisites: postpone fox/0.2.0
           trace: collect_build_postponed (0): begin
           trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
-          %.*
           trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
           trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
           trace: collect_build_prerequisites: begin libfoo/1.0.0
@@ -12794,7 +12545,6 @@ test.arguments += --sys-no-query
           trace: collect_build_postponed (1): index 1 collect alt-postponed fox/0.2.0
           trace: collect_build_prerequisites: resume fox/0.2.0
           trace: collect_build_prerequisites: dependency alternative 1,1 for dependent fox/0.2.0 is unacceptable, skipping
-          %.*
           trace: collect_build_prerequisites: alt-postpone dependent fox/0.2.0 since max index is reached: 1
             info: dependency alternative: libfoo
           {
@@ -12802,27 +12552,26 @@ test.arguments += --sys-no-query
             {
               config.libfoo.extras = true
             }
-
             accept (true)
           }
           trace: collect_build_prerequisites: postpone fox/0.2.0
           trace: collect_build_postponed (1): index 2 collect alt-postponed fox/0.2.0
           trace: collect_build_prerequisites: resume fox/0.2.0
           trace: collect_build_prerequisites: dependency alternative 1,1 for dependent fox/0.2.0 is unacceptable, skipping
-          %.*
           trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent fox/0.2.0
-          %.*
           trace: postponed_configurations::add: add {fox 1,2: libfoo} to {foo | libfoo->{foo/1,1}}!
           trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent fox/0.2.0 is negotiated
           trace: collect_build_prerequisites: dependency libfoo/1.0.0 of dependent fox/0.2.0 is already (being) recursively collected, skipping
           trace: collect_build_prerequisites: end fox/0.2.0
           trace: collect_build_postponed (1): end {foo | libfoo->{foo/1,1}}
           trace: collect_build_postponed (0): end
+          trace: execute_plan: simulate: yes
           %.*
           build plan:
             new libfoo/1.0.0 (required by foo, fox)
               config.libfoo.extras=true (set by foo)
             new foo/1.0.0
+              config.foo.libfoo_extras=true (set by foo)
             new fox/0.2.0
           trace: execute_plan: simulate: no
           %.*
@@ -12935,10 +12684,9 @@ test.arguments += --sys-no-query
             libfoo configured !0.1.0 available 1.0.0
         EOO
 
-      $* --upgrade --recursive 2>>~%EOE%;
+      $* --upgrade --recursive 2>&1 | $filter 2>>~%EOE%;
         %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add tix/1.0.0
         trace: collect_build_prerequisites: skip configured tix/1.0.0
         trace: execute_plan: simulate: yes
@@ -12946,11 +12694,8 @@ test.arguments += --sys-no-query
         trace: evaluate_dependency: libfoo/0.1.0: update to libfoo/1.0.0
         %.*
         trace: pkg_build: refine package collection/plan execution
-        %.*
         trace: collect_build: add libfoo/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build: add libbar/1.0.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libfoo/1.0.0
@@ -12958,50 +12703,38 @@ test.arguments += --sys-no-query
         trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tix/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tix/1.0.0: 1,1
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tex/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tex^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tex/1.0.0 results in {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluated tex/1.0.0
         trace: collect_build_prerequisites: reeval tix/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tix^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tix/1.0.0 results in {tex^ tix^ | libbar->{tex/1,1 tix/1,1}}
         trace: collect_build_prerequisites: re-evaluated tix/1.0.0
         trace: collect_build_postponed (1): cfg-negotiate begin {tex^ tix^ | libbar->{tex/1,1 tix/1,1}}
-        %.*
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: skip configured libbar/1.0.0
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
         trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent tex/1.0.0
         trace: collect_build_prerequisites: resume tex/1.0.0
-        %.*
         trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
         trace: collect_build_prerequisites: postpone tex/1.0.0
         trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent tix/1.0.0
         trace: collect_build_prerequisites: resume tix/1.0.0
-        %.*
         trace: collect_build_prerequisites: cannot cfg-postpone dependency tex/1.0.0 of dependent tix/1.0.0 (collected prematurely), throwing postpone_dependency
         trace: pkg_build: collection failed due to prematurely collected dependency (tex), retry from scratch
-        %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add tix/1.0.0
         trace: collect_build_prerequisites: skip configured tix/1.0.0
         trace: collect_build: add libfoo/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build: add libbar/1.0.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libfoo/1.0.0
@@ -13009,17 +12742,13 @@ test.arguments += --sys-no-query
         trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tix/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tix/1.0.0: 1,1
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex of dependency libbar
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tix/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tix^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tix/1.0.0 results in {tex^ tix^ | libbar->{tex/1,1 tix/1,1}}
         trace: collect_build_prerequisites: re-evaluated tix/1.0.0
@@ -13032,23 +12761,19 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent tix/1.0.0
         trace: collect_build_prerequisites: resume tix/1.0.0
-        %.*
         trace: collect_build_prerequisites: cfg-postpone dependency tex/1.0.0 of dependent tix/1.0.0
         trace: postponed_configurations::add: create {tix | tex->{tix/2,1}}
         trace: collect_build_prerequisites: postpone tix/1.0.0
         trace: collect_build_postponed (1): cfg-negotiate end {tex^ tix^ | libbar->{tex/1,1 tix/1,1}}!
         trace: collect_build_postponed (2): begin {tix | tex->{tix/2,1}}
-        %.*
         trace: collect_build_postponed (2): skip being built existing dependent tix of dependency tex
         trace: collect_build_postponed (2): cfg-negotiate begin {tix | tex->{tix/2,1}}
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: add {tex 1,1: libbar} to {tex^ tix^ | libbar->{tex/1,1 tix/1,1}}!
         trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent tex/1.0.0 is negotiated
         trace: collect_build_prerequisites: dependency libbar/1.0.0 of dependent tex/1.0.0 is already (being) recursively collected, skipping
-        %.*
         trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
@@ -13059,10 +12784,8 @@ test.arguments += --sys-no-query
         trace: collect_build_prerequisites: end tix/1.0.0
         trace: collect_build_postponed (2): cfg-negotiate end {tix | tex->{tix/2,1}}!
         trace: collect_build_postponed (3): begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): skip being built existing dependent tex of dependency libfoo
         trace: collect_build_postponed (3): cfg-negotiate begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin libfoo/1.0.0
         trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -13075,7 +12798,6 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): end {tix | tex->{tix/2,1}}
         trace: collect_build_postponed (1): end {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): end
-        %.*
         trace: execute_plan: simulate: yes
         %.*
         build plan:
@@ -13083,6 +12805,7 @@ test.arguments += --sys-no-query
             config.libfoo.extras=true (set by tex)
           reconfigure/update tex/1.0.0 (dependent of libfoo)
             config.tex.extras=true (set by tix)
+            config.tex.libfoo_extras=true (set by tex)
           reconfigure/update tix/1.0.0
         trace: execute_plan: simulate: no
         %.*
@@ -13125,10 +12848,9 @@ test.arguments += --sys-no-query
             libfoo configured !0.1.0 available 1.0.0
         EOO
 
-      $* --upgrade --recursive 2>>~%EOE%;
+      $* --upgrade --recursive 2>&1 | $filter 2>>~%EOE%;
         %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add tiz/1.0.0
         trace: collect_build_prerequisites: skip configured tiz/1.0.0
         trace: execute_plan: simulate: yes
@@ -13136,11 +12858,8 @@ test.arguments += --sys-no-query
         trace: evaluate_dependency: libfoo/0.1.0: update to libfoo/1.0.0
         %.*
         trace: pkg_build: refine package collection/plan execution
-        %.*
         trace: collect_build: add libfoo/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build: add libbar/1.0.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libfoo/1.0.0
@@ -13148,32 +12867,23 @@ test.arguments += --sys-no-query
         trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tex/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tex^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tex/1.0.0 results in {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluated tex/1.0.0
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: cannot re-evaluate existing dependent tiz/1.0.0 due to dependency tex/1.0.0 (collected prematurely), throwing postpone_dependency
         trace: pkg_build: collection failed due to prematurely collected dependency (tex), retry from scratch
-        %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add tiz/1.0.0
         trace: collect_build_prerequisites: skip configured tiz/1.0.0
         trace: collect_build: add libfoo/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build: add libbar/1.0.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libfoo/1.0.0
@@ -13181,52 +12891,40 @@ test.arguments += --sys-no-query
         trace: postponed_configurations::add: create {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex of dependency libbar
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: postponed_configurations::add: create {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tiz/1.0.0 results in {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluated tiz/1.0.0
         trace: collect_build_postponed (1): cfg-negotiate begin {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
-        %.*
         trace: collect_build_prerequisites: skip configured libbar/1.0.0
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): cfg-negotiate end {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_postponed (2): begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): skip being built existing dependent tiz of dependency tex
         trace: collect_build_postponed (2): cfg-negotiate begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: add {tex 1,1: libbar} to {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_prerequisites: cfg-postponing dependent tex/1.0.0 involves (being) negotiated configurations and results in {tex^ | libbar->{tex/1,1}}!, throwing retry_configuration
         trace: collect_build_postponed (0): cfg-negotiation of {tex^ | libbar->{tex/1,1}} failed due to dependent tex, refining configuration
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex of dependency libbar
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: postponed_configurations::add: create {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tiz/1.0.0 results in {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluated tiz/1.0.0
@@ -13238,17 +12936,14 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): cfg-negotiate end {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_postponed (2): begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): skip being built existing dependent tiz of dependency tex
         trace: collect_build_postponed (2): cfg-negotiate begin {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: add {tex 1,1: libbar} to {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent tex/1.0.0 is negotiated
         trace: collect_build_prerequisites: dependency libbar/1.0.0 of dependent tex/1.0.0 is already (being) recursively collected, skipping
-        %.*
         trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
@@ -13256,7 +12951,6 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
         trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent tiz/1.0.0
         trace: collect_build_prerequisites: resume tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tiz/1.0.0
         trace: postponed_configurations::add: add {tiz 2,1: libbar} to {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent tiz/1.0.0 is negotiated
@@ -13264,10 +12958,8 @@ test.arguments += --sys-no-query
         trace: collect_build_prerequisites: end tiz/1.0.0
         trace: collect_build_postponed (2): cfg-negotiate end {tiz^ | tex->{tiz/1,1}}!
         trace: collect_build_postponed (3): begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): skip being built existing dependent tex of dependency libfoo
         trace: collect_build_postponed (3): cfg-negotiate begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin libfoo/1.0.0
         trace: collect_build_prerequisites: end libfoo/1.0.0
@@ -13280,7 +12972,6 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): end {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_postponed (1): end {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): end
-        %.*
         trace: execute_plan: simulate: yes
         %.*
         build plan:
@@ -13288,7 +12979,9 @@ test.arguments += --sys-no-query
             config.libfoo.extras=true (set by tex)
           reconfigure/update tex/1.0.0 (dependent of libfoo)
             config.tex.extras=true (set by tiz)
+            config.tex.libfoo_extras=true (set by tex)
           reconfigure/update tiz/1.0.0
+            config.tiz.tex_extras=true (set by tiz)
         trace: execute_plan: simulate: no
         %.*
         EOE
@@ -14324,18 +14017,14 @@ test.arguments += --sys-no-query
             libfoo configured 1.0.0
         EOO
 
-      $* --upgrade --recursive 2>>~%EOE%;
+      $* --upgrade --recursive 2>&1 | $filter 2>>~%EOE%;
         %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add libbar/1.0.0
         trace: collect_build: add tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libbar/1.0.0
         trace: collect_build: add tex/1.0.0
@@ -14345,35 +14034,25 @@ test.arguments += --sys-no-query
         trace: collect_build_prerequisites: skip configured tiz/1.0.0
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tex/1.0.0
-        %.*
         trace: collect_build: pick libbar/1.0.0 over libbar/0.1.0
         trace: postponed_configurations::add: add {tex^ 1,1: libbar} to {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tex/1.0.0 results in {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: re-evaluated tex/1.0.0
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: cannot re-evaluate existing dependent tiz/1.0.0 due to dependency tex/1.0.0 (collected prematurely), throwing postpone_dependency
         trace: pkg_build: collection failed due to prematurely collected dependency (tex), retry from scratch
-        %.*
         trace: pkg_build: refine package collection/plan execution from scratch
-        %.*
         trace: collect_build: add libbar/1.0.0
         trace: collect_build: add tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of existing dependent tex/1.0.0 due to dependency libbar/1.0.0
         trace: collect_build: add tex/1.0.0
@@ -14383,54 +14062,42 @@ test.arguments += --sys-no-query
         trace: collect_build_prerequisites: skip configured tiz/1.0.0
         trace: collect_build_postponed (0): begin
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex of dependency libbar
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tiz^ 1,1: tex} to {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tiz/1.0.0 results in {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluated tiz/1.0.0
         trace: collect_build_postponed (1): cfg-negotiate begin {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
-        %.*
         trace: collect_build_prerequisites: begin libbar/1.0.0
         trace: collect_build_prerequisites: end libbar/1.0.0
         trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): cfg-negotiate end {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_postponed (2): begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): skip being built existing dependent tiz of dependency tex
         trace: collect_build_postponed (2): cfg-negotiate begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin tex/1.0.0
-        %.*
         trace: collect_build: pick libbar/1.0.0 over libbar/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: add {tex 1,1: libbar} to {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_prerequisites: cfg-postponing dependent tex/1.0.0 involves (being) negotiated configurations and results in {tex^ | libbar->{tex/1,1}}!, throwing retry_configuration
         trace: collect_build_postponed (0): cfg-negotiation of {tex^ | libbar->{tex/1,1}} failed due to dependent tex, refining configuration
         trace: collect_build_postponed (1): begin {tex^ | libbar->{tex/1,1}}
-        %.*
         trace: collect_build_prerequisites: pre-reeval tex/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tex/1.0.0: 1,1
         trace: collect_build_prerequisites: pre-reeval tiz/1.0.0
-        %.*
         trace: collect_build_prerequisites: pre-reevaluated tiz/1.0.0: 1,1
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex of dependency libbar
         trace: collect_build_postponed (1): re-evaluate existing dependents for {tex^ | libbar->{tex/1,1}}
         trace: collect_build_prerequisites: reeval tiz/1.0.0
-        %.*
         trace: postponed_configurations::add: add {tiz^ 1,1: tex} to {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluating dependent tiz/1.0.0 results in {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_prerequisites: re-evaluated tiz/1.0.0
@@ -14443,18 +14110,15 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (1): skip dep-postponed existing dependent tex
         trace: collect_build_postponed (1): cfg-negotiate end {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_postponed (2): begin {tiz^ | tex->{tiz/1,1}}
-        %.*
         trace: collect_build_postponed (2): skip being built existing dependent tiz of dependency tex
         trace: collect_build_postponed (2): cfg-negotiate begin {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: begin tex/1.0.0
-        %.*
         trace: collect_build: pick libbar/1.0.0 over libbar/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: add {tex 1,1: libbar} to {tex^ | libbar->{tex/1,1}}!
         trace: collect_build_prerequisites: configuration for cfg-postponed dependencies of dependent tex/1.0.0 is negotiated
         trace: collect_build_prerequisites: dependency libbar/1.0.0 of dependent tex/1.0.0 is already (being) recursively collected, skipping
-        %.*
         trace: collect_build: add libfoo/1.0.0
         trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent tex/1.0.0
         trace: postponed_configurations::add: create {tex | libfoo->{tex/2,1}}
@@ -14462,7 +14126,6 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
         trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent tiz/1.0.0
         trace: collect_build_prerequisites: resume tiz/1.0.0
-        %.*
         trace: collect_build: pick libbar/1.0.0 over libbar/0.1.0
         trace: collect_build_prerequisites: cfg-postpone dependency libbar/1.0.0 of dependent tiz/1.0.0
         trace: postponed_configurations::add: add {tiz 2,1: libbar} to {tex^ | libbar->{tex/1,1}}!
@@ -14471,10 +14134,8 @@ test.arguments += --sys-no-query
         trace: collect_build_prerequisites: end tiz/1.0.0
         trace: collect_build_postponed (2): cfg-negotiate end {tiz^ | tex->{tiz/1,1}}!
         trace: collect_build_postponed (3): begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): skip being built existing dependent tex of dependency libfoo
         trace: collect_build_postponed (3): cfg-negotiate begin {tex | libfoo->{tex/2,1}}
-        %.*
         trace: collect_build_postponed (3): recursively collect cfg-negotiated dependencies
         trace: collect_build_prerequisites: skip configured libfoo/1.0.0
         trace: collect_build_postponed (3): recursively collect cfg-negotiated dependents
@@ -14486,7 +14147,6 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): end {tiz^ | tex->{tiz/1,1}}
         trace: collect_build_postponed (1): end {tex^ | libbar->{tex/1,1}}
         trace: collect_build_postponed (0): end
-        %.*
         trace: execute_plan: simulate: yes
         %.*
         build plan:
@@ -14494,7 +14154,9 @@ test.arguments += --sys-no-query
             config.libbar.extras=true (set by tex)
           reconfigure/update tex/1.0.0 (dependent of libbar)
             config.tex.extras=true (set by tiz)
+            config.tex.libfoo_extras=true (set by tex)
           reconfigure/update tiz/1.0.0
+            config.tiz.tex_extras=true (set by tiz)
         trace: execute_plan: simulate: no
         %.*
         EOE
@@ -14530,7 +14192,7 @@ test.arguments += --sys-no-query
       #
       #  tez: depends: libbox(c)
       #       depends: toz == 0.1.0 (c)
-      #       depends: libbar
+      #       depends: libbar (c)
       #
       #  toz/0.1.0:
       #
@@ -14700,7 +14362,6 @@ test.arguments += --sys-no-query
         trace: execute_plan: simulate: yes
         %.*
         trace: evaluate_dependency: libbaz/1.0.0: unused
-        %.*
         trace: pkg_build: refine package collection/plan execution from scratch
         trace: collect_build: add tez/1.0.0
         trace: collect_build_prerequisites: begin tez/1.0.0
@@ -14850,12 +14511,16 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): end {tez | toz->{tez/2,1}}
         trace: collect_build_postponed (1): end {tez | libbox->{tez/1,1}}
         trace: collect_build_postponed (0): end
-        %.*
         trace: execute_plan: simulate: yes
         %.*
         build plan:
           new libbox/1.0.0 (required by tez)
             config.libbox.extras=true (set by tez)
+          reconfigure/update tex/1.0.0 (required by tiz)
+            config.tex.extras=true (set by tiz)
+            config.tex.libfoo_extras=true (set by tex)
+          reconfigure tiz/1.0.0 (dependent of libbar)
+            config.tiz.tex_extras=true (set by tiz)
           drop libbaz/1.0.0 (unused)
           downgrade toz/0.1.0 (required by tez)
             config.toz.extras=true (set by tez)
@@ -15274,12 +14939,16 @@ test.arguments += --sys-no-query
         trace: collect_build_postponed (2): end {tuz^ | toz->{tuz/1,1}}
         trace: collect_build_postponed (1): end {tix | libbar->{tix/1,1}}
         trace: collect_build_postponed (0): end
-        %.*
         trace: execute_plan: simulate: yes
         %.*
         build plan:
           new libbaz/1.0.0 (required by toz)
             config.libbaz.extras=true (set by toz)
+          reconfigure/update tex/1.0.0 (required by tix, tiz)
+            config.tex.extras=true (set by tix)
+            config.tex.libfoo_extras=true (set by tex)
+          reconfigure tiz/1.0.0 (dependent of libbar)
+            config.tiz.tex_extras=true (set by tiz)
           new tix/1.0.0
           upgrade toz/1.0.0
             config.toz.extras=true (set by tuz)
@@ -17813,6 +17482,7 @@ test.arguments += --sys-no-query
           upgrade libbar/1.0.0
             config.libbar.extras=true (set by bax)
           reconfigure/update bax/1.0.0
+            config.bax.libfoo_extras=true (set by bax)
           upgrade libbiz/1.0.0
         trace: execute_plan: simulate: no
         %.*
@@ -17831,6 +17501,187 @@ test.arguments += --sys-no-query
       $pkg_drop libbar libbiz bax
     }
 
+    : optimization
+    :
+    {
+      +$clone_cfg
+
+      : dependency-after-config-clause
+      :
+      {
+        $clone_cfg;
+
+        $* tax ?libfoo/0.1.0 2>!;
+
+        $pkg_status -r >>EOO;
+          !tax configured 1.0.0
+            libbar configured 1.0.0
+            libfoo configured !0.1.0 available 1.0.0
+          EOO
+
+        $* ?libfoo 2>&1 | $filter 2>>~%EOE%;
+          %.*
+          trace: pkg_build: refine package collection/plan execution from scratch
+          trace: execute_plan: simulate: yes
+          trace: evaluate_dependency: libfoo/0.1.0: update to libfoo/1.0.0
+          trace: pkg_build: refine package collection/plan execution
+          trace: collect_build_prerequisites: pre-reeval tax/1.0.0
+          trace: collect_build_prerequisites: pre-reevaluated tax/1.0.0: 1,1 re-evaluation is optional
+          trace: collect_build_prerequisites: begin libfoo/1.0.0
+          trace: collect_build_prerequisites: end libfoo/1.0.0
+          trace: execute_plan: simulate: yes
+          %.*
+          build plan:
+            upgrade libfoo/1.0.0
+            reconfigure tax (dependent of libfoo)
+          trace: execute_plan: simulate: no
+          %.*
+          EOE
+
+        $pkg_status -r >>EOO;
+          !tax configured 1.0.0
+            libbar configured 1.0.0
+            libfoo configured 1.0.0
+          EOO
+
+        $pkg_drop tax
+      }
+
+      : dependency-before-config-clause
+      :
+      {
+        $clone_cfg;
+
+        $* tex/0.2.0 ?libbar/0.1.0 2>!;
+
+        $pkg_status -r >>EOO;
+          !tex configured !0.2.0 available 1.0.0 0.3.0
+            libbar configured !0.1.0 available 1.0.0
+            libfoo configured 1.0.0
+          EOO
+
+        $* ?libbar 2>&1 | $filter 2>>~%EOE%;
+          %.*
+          trace: pkg_build: refine package collection/plan execution from scratch
+          trace: execute_plan: simulate: yes
+          trace: evaluate_dependency: libbar/0.1.0: update to libbar/1.0.0
+          trace: pkg_build: refine package collection/plan execution
+          trace: collect_build_prerequisites: pre-reeval tex/0.2.0
+          trace: collect_build_prerequisites: pre-reevaluated tex/0.2.0: 2,1 re-evaluation is optional
+          trace: collect_build_prerequisites: begin libbar/1.0.0
+          trace: collect_build_prerequisites: end libbar/1.0.0
+          trace: execute_plan: simulate: yes
+          %.*
+          build plan:
+            upgrade libbar/1.0.0
+            reconfigure tex (dependent of libbar)
+          trace: execute_plan: simulate: no
+          %.*
+          EOE
+
+        $pkg_status -r >>EOO;
+          !tex configured !0.2.0 available 1.0.0 0.3.0
+            libbar configured 1.0.0
+            libfoo configured 1.0.0
+          EOO
+
+        $pkg_drop tex
+      }
+
+      : other-config-clause
+      :
+      {
+        $clone_cfg;
+
+        $* tax ?libfoo/0.1.0 2>!;
+
+        $pkg_status -r >>EOO;
+          !tax configured 1.0.0
+            libbar configured 1.0.0
+            libfoo configured !0.1.0 available 1.0.0
+          EOO
+
+        $* libfoo foo/0.1.0 2>&1 | $filter 2>>~%EOE%;
+          %.*
+          trace: pkg_build: refine package collection/plan execution from scratch
+          trace: collect_build: add libfoo/1.0.0
+          trace: collect_build: add foo/0.1.0
+          trace: collect_build_prerequisites: pre-reeval tax/1.0.0
+          trace: collect_build_prerequisites: pre-reevaluated tax/1.0.0: 1,1 re-evaluation is optional
+          trace: collect_build_prerequisites: begin libfoo/1.0.0
+          trace: collect_build_prerequisites: end libfoo/1.0.0
+          trace: collect_build_prerequisites: begin foo/0.1.0
+          trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
+          trace: collect_build_prerequisites: cannot cfg-postpone dependency libfoo/1.0.0 of dependent foo/0.1.0 (collected prematurely), throwing postpone_dependency
+          trace: pkg_build: collection failed due to prematurely collected dependency (libfoo), retry from scratch
+          trace: pkg_build: refine package collection/plan execution from scratch
+          trace: collect_build: add libfoo/1.0.0
+          trace: collect_build: add foo/0.1.0
+          trace: pkg_build: dep-postpone user-specified libfoo
+          trace: collect_build_prerequisites: begin foo/0.1.0
+          trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
+          trace: collect_build_prerequisites: cfg-postpone dependency libfoo/1.0.0 of dependent foo/0.1.0
+          trace: postponed_configurations::add: create {foo | libfoo->{foo/1,1}}
+          trace: collect_build_prerequisites: postpone foo/0.1.0
+          trace: collect_build_postponed (0): begin
+          trace: collect_build_postponed (1): begin {foo | libfoo->{foo/1,1}}
+          trace: collect_build_prerequisites: pre-reeval tax/1.0.0
+          trace: collect_build_prerequisites: pre-reevaluated tax/1.0.0: 1,1 re-evaluation is optional
+          trace: collect_build: add libbar/1.0.0
+          trace: collect_build_postponed (1): re-evaluate existing dependents for {foo | libfoo->{foo/1,1}}
+          trace: collect_build: add tax/1.0.0
+          trace: collect_build_prerequisites: reeval tax/1.0.0
+          trace: postponed_configurations::add: create {tax^ | libbar->{tax/1,1}}
+          trace: collect_build_prerequisites: re-evaluating dependent tax/1.0.0 results in {tax^ | libbar->{tax/1,1}}
+          trace: collect_build_prerequisites: re-evaluated tax/1.0.0
+          trace: collect_build_postponed (1): cfg-negotiate begin {foo | libfoo->{foo/1,1}}
+          trace: collect_build_postponed (1): recursively collect cfg-negotiated dependencies
+          trace: collect_build_prerequisites: begin libfoo/1.0.0
+          trace: collect_build_prerequisites: end libfoo/1.0.0
+          trace: collect_build_postponed (1): recursively collect cfg-negotiated dependents
+          trace: collect_build_postponed (1): select cfg-negotiated dependency alternative for dependent foo/0.1.0
+          trace: collect_build_prerequisites: resume foo/0.1.0
+          trace: collect_build_prerequisites: end foo/0.1.0
+          trace: collect_build_postponed (1): cfg-negotiate end {foo | libfoo->{foo/1,1}}!
+          trace: collect_build_postponed (2): begin {tax^ | libbar->{tax/1,1}}
+          trace: collect_build_postponed (2): skip being built existing dependent tax of dependency libbar
+          trace: collect_build_postponed (2): cfg-negotiate begin {tax^ | libbar->{tax/1,1}}
+          trace: collect_build_postponed (2): recursively collect cfg-negotiated dependencies
+          trace: collect_build_prerequisites: skip configured libbar/1.0.0
+          trace: collect_build_postponed (2): recursively collect cfg-negotiated dependents
+          trace: collect_build_postponed (2): select cfg-negotiated dependency alternative for dependent tax/1.0.0
+          trace: collect_build_prerequisites: resume tax/1.0.0
+          trace: collect_build: pick libfoo/1.0.0 over libfoo/0.1.0
+          trace: collect_build_prerequisites: dep-postpone dependency libfoo/1.0.0 of dependent tax/1.0.0
+          trace: collect_build_prerequisites: end tax/1.0.0
+          trace: collect_build_postponed (2): cfg-negotiate end {tax^ | libbar->{tax/1,1}}!
+          trace: collect_build_postponed (2): end {tax^ | libbar->{tax/1,1}}
+          trace: collect_build_postponed (1): end {foo | libfoo->{foo/1,1}}
+          trace: collect_build_postponed (0): end
+          trace: execute_plan: simulate: yes
+          %.*
+          build plan:
+            upgrade libfoo/1.0.0
+              config.libfoo.extras=true (set by foo)
+            reconfigure tax/1.0.0 (dependent of libfoo)
+            new foo/0.1.0
+          trace: execute_plan: simulate: no
+          %.*
+          EOE
+
+        $pkg_status -r >>EOO;
+          !libfoo configured 1.0.0
+          !tax configured 1.0.0
+            libbar configured 1.0.0
+            !libfoo configured 1.0.0
+          !foo configured !0.1.0 available 1.0.0 0.2.0
+            !libfoo configured 1.0.0
+          EOO
+
+        $pkg_drop tax foo libfoo
+      }
+    }
+
     : repo-packages
     :
     : Don't match the tracing but just make sure that pkg-build doesn't crash