Add support for linked configurations

26 files changed, 2517 insertions, 8 deletions

diff --git a/tests/cfg-create.testscript b/tests/cfg-create.testscript
index 9461dad..b96a98f 100644
--- a/tests/cfg-create.testscript
+++ b/tests/cfg-create.testscript
@@ -5,6 +5,11 @@
 
 config_cxx = config.cxx=$quote($recall($cxx.path) $cxx.config.mode, true)
 
+cfg_create += 2>!
+
+# @@ To verify the creation result use cfg-list command rather than
+#    pkg-status, when implemented.
+#
 pkg_status += -d cfg
 
 : non-empty
@@ -25,6 +30,8 @@ EOE
   {
     $* 2>>/~%EOE%;
       %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
       EOE
 
     $pkg_status libfoo >'libfoo unknown'
@@ -35,6 +42,8 @@ EOE
   {
     $* "config.install.root='$~/opt'" 2>>/~%EOE%;
       %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
       EOE
 
     $pkg_status libfoo >'libfoo unknown';
@@ -51,6 +60,8 @@ EOE
   {
     $* cxx $config_cxx 2>>/~%EOE%;
       %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
       EOE
 
     $pkg_status libfoo >'libfoo unknown';
@@ -69,6 +80,8 @@ EOE
 
     $* --wipe 2>>/~%EOE%;
       %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
       EOE
 
     $pkg_status libfoo >'libfoo unknown'
@@ -81,8 +94,126 @@ EOE
 
     $* --existing 2>>/~%EOE%;
       %initialized existing configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
+      EOE
+
+    $pkg_status libfoo >'libfoo unknown'
+  }
+}
+
+: name
+:
+{
+  test.arguments += -d cfg
+
+  : valid
+  :
+  {
+    $* --name foo 2>>/~%EOE% &cfg/***;
+      %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
+        info: name: foo
+      EOE
+
+    # @@ To verify the result use cfg-list, when implemented.
+    #
+    $pkg_status libfoo >'libfoo unknown'
+  }
+
+  : invalid
+  :
+  : Also use the short option.
+  :
+  $* --name 123 2>>EOE != 0
+    error: invalid --name option value '123': illegal first character (must be alphabetic or underscore)
+    EOE
+}
+
+: type
+:
+{
+  test.arguments += -d cfg
+
+  : valid
+  :
+  {
+    $* --type host 2>>/~%EOE% &cfg/***;
+      %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: host
       EOE
 
     $pkg_status libfoo >'libfoo unknown'
   }
+
+  : invalid
+  :
+  : Also use the short option.
+  :
+  $* --type '' 2>>EOE != 0
+    error: empty --type option value
+    EOE
+}
+
+: uuid
+:
+{
+  test.arguments += -d cfg
+
+  : valid
+  :
+  {
+    $* --config-uuid '18f48b4b-b5d9-4712-b98c-1930df1c4228' 2>>/~%EOE% &cfg/***;
+      %created new configuration in .+/cfg/%
+        info: uuid: 18f48b4b-b5d9-4712-b98c-1930df1c4228
+        info: type: target
+      EOE
+
+    $pkg_status libfoo >'libfoo unknown'
+  }
+
+  : invalid
+  :
+  : Also use the short option.
+  :
+  $* --config-uuid '123' 2>>EOE != 0
+    error: invalid value '123' for option '--config-uuid'
+    EOE
+}
+
+: link-config
+:
+{
+  test.arguments += -d cfg
+
+  : valid-type
+  :
+  {
+    $cfg_create -d host   --type 'host'   &host/***;
+    $cfg_create -d build2 --type 'build2' &build2/***;
+
+    $* --host-config host --build2-config build2 2>>/~%EOE% &cfg/***;
+      %created new configuration in .+/cfg/%
+      %  info: uuid: .{36}%
+        info: type: target
+      EOE
+
+    $pkg_status libfoo >'libfoo unknown'
+  }
+
+  : invalid-type
+  :
+  {
+    $cfg_create -d cfg2 &cfg2/***;
+
+    $* --host-config cfg2 2>>/~%EOE% != 0;
+      %error: host configuration .+/cfg2/ is of 'target' type%
+      EOE
+
+    $* --build2-config cfg2 2>>/~%EOE% != 0
+      %error: build2 configuration .+/cfg2/ is of 'target' type%
+      EOE
+  }
 }
diff --git a/tests/cfg-link.testscript b/tests/cfg-link.testscript
new file mode 100644
index 0000000..b396c1a
--- /dev/null
+++ b/tests/cfg-link.testscript
@@ -0,0 +1,190 @@
+# file      : tests/cfg-link.testscript
+# license   : MIT; see accompanying LICENSE file
+
+.include common.testscript
+
+cfg_create += 2>!
+
+# @@ To verify the linking result use cfg-list command rather than pkg-status,
+#    when implemented.
+#
+
+test.arguments += -d cfg
+
+cfg_uuid  = '18f48b4b-b5d9-4712-b98c-1930df1c4228'
+acfg_uuid = '28f48b4b-b5d9-4712-b98c-1930df1c4228'
+
+: success
+:
+{
+  $cfg_create -d  cfg --name 'main';
+  $cfg_create -d acfg --name 'shared' --config-uuid "$acfg_uuid" &acfg/***;
+
+  # Try to link configuration under the same name.
+  #
+  $* cfg 2>>/~"%EOE%" != 0;
+    %error: linking configuration .+/cfg/ with itself%
+    %  info: uuid: .{36}%
+    EOE
+
+  # Try to link configuration under the same name.
+  #
+  $* acfg --name 'main' 2>>/~"%EOE%" != 0;
+    %error: linking configuration .+/acfg/ using current configuration name 'main'%
+      info: consider specifying alternative name with --name
+    EOE
+
+  # Link configuration.
+  #
+  $* acfg 2>>/~"%EOE%";
+    %linked configuration .+/acfg/%
+      info: uuid: $acfg_uuid
+      info: type: target
+      info: name: shared
+      info: id:   1
+    EOE
+
+  $pkg_status -d cfg  libfoo >'libfoo unknown';
+  $pkg_status -d acfg libfoo >'libfoo unknown';
+
+  # Test that the recreated configuration can be implicitly re-linked.
+  #
+  rm -r cfg;
+  $cfg_create -d cfg --name 'test' --config-uuid "$cfg_uuid" &cfg/***;
+
+  $* acfg 2>>/~"%EOE%";
+    %warning: current configuration .+/cfg/ is already implicitly linked with .+/acfg/%
+    %linked configuration .+/acfg/%
+      info: uuid: $acfg_uuid
+      info: type: target
+      info: name: shared
+      info: id:   1
+    EOE
+
+  # Test that the repeated link is reported.
+  #
+  $* acfg 2>>/~%EOE% != 0;
+    %error: configuration with uuid .{36} is already linked as \.\./acfg/%
+    EOE
+
+  rm -r acfg;
+
+  $cfg_create -d acfg --name 'shared' &acfg/***;
+
+  # Test that the path clash is reported.
+  #
+  $* acfg 2>>/~%EOE% != 0;
+    %error: configuration with path .+/acfg/ is already linked%
+    EOE
+
+  # Test that the name clash is reported.
+  #
+  $cfg_create -d acfg2 --name 'shared' &acfg2/***;
+
+  $* acfg2 --name 'shared' 2>>/EOE != 0;
+    error: configuration with name shared is already linked as ../acfg/
+      info: consider specifying alternative name with --name
+    EOE
+
+  $* acfg2 2>>/~%EOE%;
+    warning: configuration with name shared is already linked as ../acfg/, linking as unnamed
+    %linked configuration .+/acfg2/%
+    %  info: uuid: .{36}%
+      info: type: target
+      info: id:   2
+    EOE
+
+  # Test that the integrity check fails.
+  #
+  $pkg_status -d cfg libfoo 2>>/~"%EOE%" != 0;
+    error: configuration acfg/ uuid mismatch
+    %  info: uuid .+%
+      info: linked with cfg/ as $acfg_uuid
+    EOE
+
+  # Link the second configuration.
+  #
+  rm -r acfg;
+  $cfg_create -d acfg --name 'shared' --config-uuid "$acfg_uuid" &acfg/***;
+
+  $pkg_status -d cfg   libfoo >'libfoo unknown';
+  $pkg_status -d acfg2 libfoo >'libfoo unknown';
+
+  # Test that the configuration type mismatch is reported.
+  #
+  mv cfg cfg.tmp;
+  $cfg_create -d cfg --type host --config-uuid "$cfg_uuid";
+
+  $* -d acfg2 cfg 2>>/EOE != 0;
+    error: configuration cfg/ type mismatch
+      info: type host
+      info: implicitly linked with acfg2/ as target
+    EOE
+
+  rm -r cfg;
+  mv cfg.tmp cfg;
+
+  # Make the implicit link explicit.
+  #
+  $* -d acfg2 cfg 2>>/~"%EOE%";
+    %linked configuration .+/cfg/%
+      info: uuid: $cfg_uuid
+      info: type: target
+      info: name: test
+      info: id:   1
+    EOE
+
+  $pkg_status -d cfg libfoo >'libfoo unknown';
+  $pkg_status -d acfg2 libfoo >'libfoo unknown';
+
+  $* -d acfg2 cfg 2>>/~%EOE% != 0;
+    %error: configuration with uuid .{36} is already linked as \.\./cfg/%
+    EOE
+
+  # Test that the implicit link path clash is reported.
+  #
+  rm -r cfg;
+  $cfg_create -d cfg --name 'test' &cfg/***;
+
+  $* acfg2 2>>/~%EOE% != 0;
+    %error: current configuration .+/cfg/ is already linked with .+/acfg2/%
+    EOE
+
+  # Test that the repeated implicit link is reported.
+  #
+  $cfg_create -d cfg2 --config-uuid "$cfg_uuid";
+
+  $* -d cfg2 acfg2 2>>/~"%EOE%" != 0;
+    %error: current configuration $cfg_uuid is already linked with .+/acfg2/%
+    EOE
+
+  # Make sure that current configuration is implicitly linked as unnamed.
+  #
+  # @@ Make sure that's really the case when the cfg-list command is
+  #    implemented.
+  #
+  rm -r cfg2;
+  $cfg_create -d cfg2 --name 'test' &cfg2/***;
+
+  $* -d cfg2 acfg2 2>>/~%EOE%;
+    %linked configuration .+/acfg2/%
+    %  info: uuid: .{36}%
+      info: type: target
+      info: name: shared
+      info: id:   1
+    EOE
+
+  # Test that the integrity check fails.
+  #
+  $pkg_status -d cfg2 libfoo 2>>/~"%EOE%" != 0;
+    error: configuration cfg/ uuid mismatch
+    %  info: uuid .+%
+      info: linked with acfg2/ as $cfg_uuid
+    EOE
+
+  rm -r cfg;
+  $cfg_create -d cfg --name 'test' --config-uuid "$cfg_uuid" &cfg/***;
+
+  $pkg_status -d cfg2  libfoo >'libfoo unknown';
+  $pkg_status -d acfg2 libfoo >'libfoo unknown'
+}
diff --git a/tests/common.testscript b/tests/common.testscript
index 5db8c6a..105bf3e 100644
--- a/tests/common.testscript
+++ b/tests/common.testscript
@@ -33,6 +33,7 @@ test.options += --default-options $options_guard \
 # as expected).
 #
 cfg_create    = $* cfg-create
+cfg_link      = $* cfg-link
 pkg_build     = $* pkg-build
 pkg_checkout  = $* pkg-checkout
 pkg_configure = $* pkg-configure
diff --git a/tests/common/linked/t7a/foo-1.0.0.tar.gz b/tests/common/linked/t7a/foo-1.0.0.tar.gz
new file mode 100644
index 0000000..100496d
--- /dev/null
+++ b/tests/common/linked/t7a/foo-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbar-1.0.0.tar.gz b/tests/common/linked/t7a/libbar-1.0.0.tar.gz
new file mode 100644
index 0000000..21940a3
--- /dev/null
+++ b/tests/common/linked/t7a/libbar-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbaz-1.0.0.tar.gz b/tests/common/linked/t7a/libbaz-1.0.0.tar.gz
new file mode 100644
index 0000000..723ac32
--- /dev/null
+++ b/tests/common/linked/t7a/libbaz-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbix-1.0.0.tar.gz b/tests/common/linked/t7a/libbix-1.0.0.tar.gz
new file mode 100644
index 0000000..67dd873
--- /dev/null
+++ b/tests/common/linked/t7a/libbix-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbiz-1.0.0.tar.gz b/tests/common/linked/t7a/libbiz-1.0.0.tar.gz
new file mode 100644
index 0000000..1214925
--- /dev/null
+++ b/tests/common/linked/t7a/libbiz-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbox-1.0.0.tar.gz b/tests/common/linked/t7a/libbox-1.0.0.tar.gz
new file mode 100644
index 0000000..7c293e0
--- /dev/null
+++ b/tests/common/linked/t7a/libbox-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbuild2-bar-1.0.0.tar.gz b/tests/common/linked/t7a/libbuild2-bar-1.0.0.tar.gz
new file mode 100644
index 0000000..789b4e8
--- /dev/null
+++ b/tests/common/linked/t7a/libbuild2-bar-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbuild2-foo-1.0.0.tar.gz b/tests/common/linked/t7a/libbuild2-foo-1.0.0.tar.gz
new file mode 100644
index 0000000..d7032d0
--- /dev/null
+++ b/tests/common/linked/t7a/libbuild2-foo-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libbuz-1.0.0.tar.gz b/tests/common/linked/t7a/libbuz-1.0.0.tar.gz
new file mode 100644
index 0000000..4d0ea38
--- /dev/null
+++ b/tests/common/linked/t7a/libbuz-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libfax-1.0.0.tar.gz b/tests/common/linked/t7a/libfax-1.0.0.tar.gz
new file mode 100644
index 0000000..a460e4a
--- /dev/null
+++ b/tests/common/linked/t7a/libfax-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/libfix-1.0.0.tar.gz b/tests/common/linked/t7a/libfix-1.0.0.tar.gz
new file mode 100644
index 0000000..fbfadde
--- /dev/null
+++ b/tests/common/linked/t7a/libfix-1.0.0.tar.gz
diff --git a/tests/common/linked/t7a/repositories.manifest b/tests/common/linked/t7a/repositories.manifest
new file mode 100644
index 0000000..5b70556
--- /dev/null
+++ b/tests/common/linked/t7a/repositories.manifest
@@ -0,0 +1 @@
+: 1
diff --git a/tests/common/linked/t7b/foo-1.1.0.tar.gz b/tests/common/linked/t7b/foo-1.1.0.tar.gz
new file mode 100644
index 0000000..aa929fb
--- /dev/null
+++ b/tests/common/linked/t7b/foo-1.1.0.tar.gz
diff --git a/tests/common/linked/t7b/libbar-1.1.0.tar.gz b/tests/common/linked/t7b/libbar-1.1.0.tar.gz
new file mode 100644
index 0000000..9926348
--- /dev/null
+++ b/tests/common/linked/t7b/libbar-1.1.0.tar.gz
diff --git a/tests/common/linked/t7b/libbaz-1.1.0.tar.gz b/tests/common/linked/t7b/libbaz-1.1.0.tar.gz
new file mode 100644
index 0000000..6b12460
--- /dev/null
+++ b/tests/common/linked/t7b/libbaz-1.1.0.tar.gz
diff --git a/tests/common/linked/t7b/libbox-1.1.0.tar.gz b/tests/common/linked/t7b/libbox-1.1.0.tar.gz
new file mode 100644
index 0000000..698661d
--- /dev/null
+++ b/tests/common/linked/t7b/libbox-1.1.0.tar.gz
diff --git a/tests/common/linked/t7b/repositories.manifest b/tests/common/linked/t7b/repositories.manifest
new file mode 100644
index 0000000..aed60ed
--- /dev/null
+++ b/tests/common/linked/t7b/repositories.manifest
@@ -0,0 +1,4 @@
+: 1
+location: ../t7a
+role: complement
+:
diff --git a/tests/pkg-build.testscript b/tests/pkg-build.testscript
index 64e6af8..a632b67 100644
--- a/tests/pkg-build.testscript
+++ b/tests/pkg-build.testscript
@@ -113,6 +113,30 @@
 # |   |   `-- root.build
 # |   `-- *
 # |
+# |-- t7a
+# |   |-- libbaz-1.0.0.tar.gz
+# |   |-- foo-1.0.0.tar.gz            -> libbaz ^1.0.0
+# |   |-- libbuild2-bar-1.0.0.tar.gz
+# |   |-- libbuild2-foo-1.0.0.tar.gz  -> libbuild2-bar ^1.0.0, * foo ^1.0.0,
+# |   |                                  libbaz ^1.0.0
+# |   |-- libbiz-1.0.0.tar.gz         -> * libbuild2-foo ^1.0.0, * foo ^1.0.0,
+# |   |                                  libbaz ^1.0.0
+# |   |-- libbuz-1.0.0.tar.gz         -> * libbuild2-foo ^1.0.0, * foo ^1.0.0
+# |   |-- libbix-1.0.0.tar.gz         -> libbiz ^1.0.0, libbuz ^1.0.0
+# |   |-- libbar-1.0.0.tar.gz         -> * foo ^1.0.0, libbaz ^1.0.0
+# |   |-- libbox-1.0.0.tar.gz         -> * foo ^1.0.0, libbaz ^1.0.0
+# |   |-- libfax-1.0.0.tar.gz
+# |   |-- libfix-1.0.0.tar.gz         -> libbar ^1.0.0, libbox ^1.0.0,
+# |   |                                  libfax ^1.0.0
+# |   `-- repositories.manifest
+# |
+# |-- t7b                       -> t7a (complement repository)
+# |   |-- libbaz-1.1.0.tar.gz
+# |   |-- foo-1.1.0.tar.gz      -> libbaz ^1.1.0
+# |   |-- libbar-1.1.0.tar.gz   -> * foo ^1.1.0, libbaz ^1.0.0
+# |   |-- libbox-1.1.0.tar.gz   -> * foo ^1.0.0
+# |   `-- repositories.manifest
+# |
 # `-- git
 #     |-- libbar.git            -> style-basic.git (prerequisite repository)
 #     |-- libbaz.git
@@ -139,6 +163,8 @@ posix = ($cxx.target.class != 'windows')
   cp -r $src/t4e $out/t4e && $rep_create $out/t4e &$out/t4e/packages.manifest
   cp -r $src/t5  $out/t5  && $rep_create $out/t5  &$out/t5/packages.manifest
   cp -r $src/t6  $out/t6  && $rep_create $out/t6  &$out/t6/packages.manifest
+  cp -r $src/t7a $out/t7a && $rep_create $out/t7a &$out/t7a/packages.manifest
+  cp -r $src/t7b $out/t7b && $rep_create $out/t7b &$out/t7b/packages.manifest
 
   # Create git repositories.
   #
@@ -149,6 +175,8 @@ end
 
 config_cxx = config.cxx=$quote($recall($cxx.path) $cxx.config.mode, true)
 
+cfg_create    += 2>!
+cfg_link      += 2>!
 pkg_configure += -d cfg $config_cxx 2>!
 pkg_disfigure += -d cfg
 pkg_drop      += -d cfg --yes 2>!
@@ -408,6 +436,18 @@ test.options += --no-progress
     info: while satisfying libbar/1.0.0
     EOE
 
+  : unknown-dependency-config
+  :
+  : As above but with a linked configuration.
+  :
+  $clone_root_cfg;
+  $cfg_create -d cfg2 &cfg2/***;
+  $cfg_link -d cfg cfg2;
+  $* $src/libbar-1.0.0.tar.gz +{ --config-id 1 } 2>>~%EOE% != 0
+    %error: unknown dependency libfoo of package libbar \[cfg2.\]%
+    %info: while satisfying libbar/1.0.0 \[cfg2.\]%
+    EOE
+
   : t2
   :
   {
@@ -513,6 +553,21 @@ test.options += --no-progress
         EOO
     }
 
+    : latest-config
+    :
+    : As above but with a linked configuration.
+    :
+    {
+      $clone_cfg;
+      $cfg_create -d cfg2 &cfg2/***;
+      $cfg_link -d cfg cfg2;
+
+      $* libbar/1.1.0 +{ --config-id 1 } >>~%EOO%
+        %new libfoo/1.1.0\+1 \[cfg2.\] \(required by libbar \[cfg2.\]\)%
+        %new libbar/1.1.0 \[cfg2.\]%
+        EOO
+    }
+
     : zero
     :
     {
@@ -755,6 +810,24 @@ test.options += --no-progress
       info: while satisfying libbaz/1.1.0
       EOE
 
+    : unable-satisfy-config
+    :
+    : As above but with a linked configuration.
+    :
+    $clone_cfg;
+    $cfg_create -d cfg2 &cfg2/***;
+    $cfg_link -d cfg cfg2;
+    $* libbaz ?libbar +{ --config-id 1 } libfoo/1.0.0 +{ --config-id 1 } 2>>~%EOE% != 0
+      error: unable to satisfy constraints on package libfoo
+        info: command line depends on (libfoo == 1.0.0)
+      %  info: libbar \[cfg2.\] depends on \(libfoo == 1.1.0\)%
+        info: available libfoo/1.0.0
+        info: available libfoo/1.1.0
+        info: explicitly specify libfoo version to manually satisfy both constraints
+      %info: while satisfying libbar/1.1.0 \[cfg2.\]%
+      info: while satisfying libbaz/1.1.0
+      EOE
+
     : not-available
     :
     $clone_cfg;
@@ -832,6 +905,38 @@ test.options += --no-progress
       $pkg_disfigure libfoo 2>'disfigured libfoo/1.1.0';
       $pkg_purge     libfoo 2>'purged libfoo/1.1.0'
     }
+
+    : unable-downgrade-config
+    :
+    : As above but with a linked configuration.
+    :
+    {
+      $clone_cfg;
+      $cfg_create -d cfg2 &cfg2/***;
+      $rep_add -d cfg2 $rep/t4c && $rep_fetch -d cfg2;
+      $cfg_link -d cfg2 cfg;
+      $pkg_fetch libfoo/1.1.0 && $pkg_unpack libfoo && $pkg_configure libfoo;
+      $pkg_fetch libbar/1.1.0 && $pkg_unpack libbar && $pkg_configure libbar;
+
+      $* libfoo-1.2.0.tar.gz 2>>EOE != 0;
+        error: unknown package libfoo-1.2.0.tar.gz
+        EOE
+
+      $* -d cfg2 libfoo/1.0.0 +{ --config-id 1 } 2>>~%EOE% != 0;
+        %error: unable to downgrade package libfoo/1.1.0 \[cfg.\] to 1.0.0%
+        %  info: because package libbar \[cfg.\] depends on \(libfoo == 1.1.0\)%
+          info: explicitly request up/downgrade of package libbar
+          info: or explicitly specify package libfoo version to manually satisfy these constraints
+        EOE
+
+      $* libfoo/1.1.0 --keep-unused >'update libfoo/1.1.0';
+
+      $pkg_disfigure libbar 2>'disfigured libbar/1.1.0';
+      $pkg_purge     libbar 2>'purged libbar/1.1.0';
+
+      $pkg_disfigure libfoo 2>'disfigured libfoo/1.1.0';
+      $pkg_purge     libfoo 2>'purged libfoo/1.1.0'
+    }
   }
 
   : dependent-reconfiguration
@@ -1166,6 +1271,37 @@ test.options += --no-progress
       $pkg_disfigure libfoo 2>'disfigured libfoo/1.0.0';
       $pkg_purge     libfoo 2>'purged libfoo/1.0.0'
     }
+
+    : forcing-upgrade-held-config
+    :
+    : As above but with a linked configuration.
+    :
+    {
+      $clone_cfg;
+      $cfg_create -d cfg2 &cfg2/***;
+      $cfg_link -d cfg cfg2;
+
+      $* libfoo/1.0.0 +{ --config-id 1 } 2>>~%EOE%;
+        %fetched libfoo/1.0.0 \[cfg2.\]%
+        %unpacked libfoo/1.0.0 \[cfg2.\]%
+        %configured libfoo/1.0.0 \[cfg2.\]%
+        %info: .+ is up to date%
+        %updated libfoo/1.0.0 \[cfg2.\]%
+        EOE
+
+      $pkg_status -d cfg2 libfoo >'!libfoo configured !1.0.0';
+
+      $* libbaz ?libbar +{ --config-id 1 } 2>>~%EOE% != 0;
+        %error: package libbar \[cfg2.\] dependency on \(libfoo == 1.1.0\) is forcing upgrade of libfoo/1.0.0 \[cfg2.\] to 1.1.0%
+        %  info: package version libfoo/1.0.0 \[cfg2.\] is held%
+          info: explicitly request version upgrade to continue
+        %info: while satisfying libbar/1.1.0 \[cfg2.\]%
+        info: while satisfying libbaz/1.1.0
+        EOE
+
+      $pkg_disfigure -d cfg2 libfoo 2>'disfigured libfoo/1.0.0';
+      $pkg_purge     -d cfg2 libfoo 2>'purged libfoo/1.0.0'
+    }
   }
 
   : drop-dependencies
@@ -2326,6 +2462,32 @@ test.options += --no-progress
 
         $pkg_drop libbar
       }
+
+      : unsatisfied-config
+      :
+      : As above but with a linked configuration.
+      :
+      {
+        $clone_cfg;
+        $cfg_create -d cfg2 &cfg2/***;
+        $cfg_link -d cfg cfg2;
+
+        $* libbar/0.0.1 2>!;
+
+        $pkg_status libbaz >'libbaz configured 0.0.1 available 0.1.0 0.0.4 0.0.3';
+
+        $* ?libbaz/0.0.3 +{ --config-id 1 } 2>>EOE != 0;
+          error: unable to satisfy constraints on package libbaz
+            info: libbar depends on (libbaz == 0.0.1)
+            info: command line depends on (libbaz == 0.0.3)
+            info: specify libbaz version to satisfy libbar constraint
+          info: while satisfying libbar/0.0.1
+          EOE
+
+        $pkg_status libbaz >'libbaz configured 0.0.1 available 0.1.0 0.0.4 0.0.3';
+
+        $pkg_drop libbar
+      }
     }
 
     : scratch
@@ -2480,7 +2642,7 @@ test.options += --no-progress
     : as a dependency, so it is built incrementally.
     :
     {
-      $cfg_create cxx $config_cxx -d cfg 2>- &cfg/***;
+      $cfg_create cxx $config_cxx -d cfg &cfg/***;
 
       # Add libhello as the dir repository.
       #
@@ -2899,7 +3061,7 @@ test.options += --no-progress
 {
   test.arguments += --yes
 
-  +$cfg_create cxx $config_cxx -d cfg 2>- &cfg/***
+  +$cfg_create cxx $config_cxx -d cfg &cfg/***
 
   : direct
   :
@@ -2918,6 +3080,27 @@ test.options += --no-progress
       EOE
   }
 
+  : direct-config
+  :
+  : As above but with a linked configuration.
+  :
+  {
+    $clone_cfg;
+    $cfg_create -d cfg2 &cfg2/***;
+    $cfg_link -d cfg cfg2;
+
+    cp -r $src/libfoo-1.1.0/ libfoo;
+    echo "depends: libfoo" >+ libfoo/manifest;
+    $rep_add libfoo --type dir;
+
+    $rep_fetch;
+
+    $* libfoo +{ --config-id 1 } 2>>~%EOE% != 0
+      %error: dependency cycle detected involving package libfoo \[cfg2.\]%
+      %  info: libfoo/1.1.0 \[cfg2.\] depends on libfoo/1.1.0 \[cfg2.\]%
+      EOE
+  }
+
   : indirect
   :
   {
@@ -2996,7 +3179,7 @@ test.options += --no-progress
 {
   test.arguments += --yes
 
-  +$cfg_create cxx $config_cxx -d cfg 2>- &cfg/***
+  +$cfg_create cxx $config_cxx -d cfg &cfg/***
   +cp -r $src/libhello-1.0.0 ./libhello
   +$rep_add libhello --type dir
   +$rep_fetch
@@ -3472,6 +3655,30 @@ test.options += --no-progress
     $pkg_drop libfoo
   }
 
+  : no-patch-config
+  :
+  : As above but with a linked configuration.
+  :
+  {
+    $clone_root_cfg;
+    $cfg_create -d cfg2 &cfg2/***;
+    $cfg_link -d cfg cfg2;
+
+    $* "libfoo@$rep/t1" +{ --config-id 1 } --patch 2>>~%EOE%;
+      %.+
+      %configured libfoo/1.0.0 \[cfg2.\]%
+      %info: .+ is up to date%
+      %updated libfoo/1.0.0 \[cfg2.\]%
+      EOE
+
+    $* "libfoo@$rep/t3" +{ --config-id 1 } --patch 2>>~%EOE% != 0;
+      %.+
+      %error: patch version for libfoo/1.0.0 \[cfg2.\] is not found in pkg:build2.org/pkg-build/t3%
+      EOE
+
+    $pkg_drop -d cfg2 libfoo
+  }
+
   : package-in-complement
   :
   {
@@ -3574,7 +3781,7 @@ test.options += --no-progress
 : keep-out
 :
 {
-  +$cfg_create cxx $config_cxx -d cfg 2>- &cfg/***
+  +$cfg_create cxx $config_cxx -d cfg &cfg/***
 
   # Build libhello as an external package.
   #
@@ -3692,7 +3899,7 @@ test.options += --no-progress
       # Distribute using the dedicated configuration to avoid the 'c and cxx
       # module toolchain pattern mismatch' warning.
       #
-      +$cfg_create cxx $config_cxx -d cfg 2>- &cfg/***
+      +$cfg_create cxx $config_cxx -d cfg &cfg/***
 
       +$build 'dist(../../libhello/@./cfg/libhello/)' \
               config.dist.root=./ \
@@ -3991,3 +4198,1689 @@ else
     $pkg_purge style-basic
   }
 }
+
+: linked-configs
+:
+{
+  : 2-configs
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t4c && $rep_fetch
+
+    : invalid-cfg
+    :
+    {
+      +$clone_cfg
+
+      : config-id
+      :
+      {
+        $clone_cfg;
+        $* libbaz --config-id 1 2>>/EOE != 0
+          error: no configuration with id 1 is linked with cfg/
+          EOE
+      }
+
+      : config-name
+      :
+      {
+        $clone_cfg;
+        $* libbaz --config-name foo 2>>/EOE != 0
+          error: no configuration with name 'foo' is linked with cfg/
+          EOE
+      }
+
+      : config-uuid
+      :
+      {
+        $clone_cfg;
+        $* libbaz --config-uuid '18f48b4b-b5d9-4712-b98c-1930df1c4228' 2>>/EOE != 0
+          error: no configuration with uuid 18f48b4b-b5d9-4712-b98c-1930df1c4228 is linked with cfg/
+          EOE
+      }
+
+      : multiple
+      :
+      {
+        $clone_cfg;
+        $* libbaz --config-id 1 --config-name foo 2>>/EOE != 0
+          error: multiple --config-* specified
+          EOE
+      }
+    }
+
+    : baz
+    :
+    {
+      $clone_cfg;
+      $cfg_create -d cfg-bar-foo &cfg-bar-foo/***;
+      $cfg_link -d cfg cfg-bar-foo;
+
+      $* libbaz ?libbar +{ --config-id 1 } ?libfoo +{ --config-id 1 } 2>>~%EOE%;
+        %fetched libfoo/1.1.0 \[cfg-bar-foo.\]%
+        %unpacked libfoo/1.1.0 \[cfg-bar-foo.\]%
+        %fetched libbar/1.1.0 \[cfg-bar-foo.\]%
+        %unpacked libbar/1.1.0 \[cfg-bar-foo.\]%
+        fetched libbaz/1.1.0
+        unpacked libbaz/1.1.0
+        %configured libfoo/1.1.0 \[cfg-bar-foo.\]%
+        %configured libbar/1.1.0 \[cfg-bar-foo.\]%
+        configured libbaz/1.1.0
+        %info: cfg-bar-foo.+libfoo-1.1.0.+ is up to date%
+        %info: cfg-bar-foo.+libbar-1.1.0.+ is up to date%
+        %info: cfg[^-].+libbaz-1.1.0.+ is up to date%
+        %updated libfoo/1.1.0 \[cfg-bar-foo.\]%
+        %updated libbar/1.1.0 \[cfg-bar-foo.\]%
+        updated libbaz/1.1.0
+        EOE
+
+      $pkg_status -r libbaz >>/EOO;
+        !libbaz configured 1.1.0
+          libbar [cfg-bar-foo/] configured 1.1.0
+            libfoo [cfg-bar-foo/] configured 1.1.0
+          libfoo [cfg-bar-foo/] configured 1.1.0
+        EOO
+
+      $pkg_status -d cfg-bar-foo -r libbar >>/EOO;
+        libbar configured 1.1.0
+          libfoo configured 1.1.0
+        EOO
+
+      $pkg_status -d cfg-bar-foo libfoo >'libfoo configured 1.1.0';
+
+      $pkg_drop libbaz;
+
+      $pkg_status libbaz libbar libfoo >>/EOO
+        libbaz available 1.1.0
+        libbar available [1.1.0]
+        libfoo available [1.1.0] 1.0.0
+        EOO
+    }
+  }
+
+  : 3-configs
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t4c && $rep_fetch
+
+    : baz
+    :
+    {
+      uuid = '28f48b4b-b5d9-4712-b98c-1930df1c4228';
+
+      $clone_cfg;
+      $cfg_create -d cfg-bar &cfg-bar/***;
+      $cfg_create -d cfg-foo --config-uuid $uuid &cfg-foo/***;
+
+      $cfg_link -d cfg     cfg-bar;
+      $cfg_link -d cfg-bar cfg-foo;
+
+      $* libbar@"$rep/t4b" -d cfg-bar ?libfoo +{ --config-id 2 } --trust-yes 2>>~%EOE%;
+        added pkg:build2.org/pkg-build/t4b
+        fetching pkg:build2.org/pkg-build/t4b
+        fetching pkg:build2.org/pkg-build/t4a (prerequisite of pkg:build2.org/pkg-build/t4b)
+        %fetched libfoo/1.1.0 \[cfg-foo.\]%
+        %unpacked libfoo/1.1.0 \[cfg-foo.\]%
+        fetched libbar/1.1.0
+        unpacked libbar/1.1.0
+        %configured libfoo/1.1.0 \[cfg-foo.\]%
+        configured libbar/1.1.0
+        %info: cfg-foo.+libfoo-1.1.0.+ is up to date%
+        %info: cfg-bar.+libbar-1.1.0.+ is up to date%
+        %updated libfoo/1.1.0 \[cfg-foo.\]%
+        updated libbar/1.1.0
+        EOE
+
+      $* libfoo --config-uuid $uuid 2>>~%EOE%;
+        %info: cfg-foo.+libfoo-1.1.0.+ is up to date%
+        %updated libfoo/1.1.0 \[cfg-foo.\]%
+        EOE
+
+      $* libbaz 2>>~%EOE%;
+        fetched libbaz/1.1.0
+        unpacked libbaz/1.1.0
+        configured libbaz/1.1.0
+        %info: cfg[^-].+libbaz-1.1.0.+ is up to date%
+        updated libbaz/1.1.0
+        EOE
+
+      $pkg_status -r >>/EOO;
+        !libbaz configured 1.1.0
+          !libbar [cfg-bar/] configured !1.1.0
+            !libfoo [cfg-foo/] configured 1.1.0
+          !libfoo [cfg-foo/] configured 1.1.0
+        !libbar [cfg-bar/] configured !1.1.0
+          !libfoo [cfg-foo/] configured 1.1.0
+        !libfoo [cfg-foo/] configured 1.1.0
+        EOO
+
+      $pkg_drop libbaz;
+
+      $* ?libfoo --config-uuid $uuid; # Unhold.
+
+      $pkg_status libbaz libbar libfoo >>/EOO;
+        libbaz available 1.1.0
+        !libbar [cfg-bar/] configured !1.1.0
+        libfoo [cfg-foo/] configured 1.1.0
+        EOO
+
+      $* ?libbar +{ --config-id 1 } <'y' 2>>~%EOE%;
+        %  drop libfoo/1.1.0 \[cfg-foo.\] \(unused\)%
+        %  drop libbar/1.1.0 \[cfg-bar.\] \(unused\)%
+        %continue\? \[Y/n\] disfigured libbar/1.1.0 \[cfg-bar.\]%
+        %disfigured libfoo/1.1.0 \[cfg-foo.\]%
+        %purged libfoo/1.1.0 \[cfg-foo.\]%
+        %purged libbar/1.1.0 \[cfg-bar.\]%
+        EOE
+
+      $pkg_status libbar libfoo >>/EOO
+        libbar available [1.1.0]
+        libfoo available [1.1.0] 1.0.0
+        EOO
+    }
+  }
+
+  : buildtime-dep
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t7a && $rep_fetch
+
+    : external-config
+    :
+    {
+      +$clone_cfg
+      +$cfg_create -d cfg2 --type host --name cfg2 &cfg2/***
+      +$cfg_link -d cfg cfg2
+
+      : downgrade-dependency
+      :
+      {
+        $clone_cfg;
+        cp -pr ../cfg2 ./;
+
+        $* libbar <'y' 2>>~%EOE%;
+          %  new libbaz/1.0.0 \[cfg2.\] \(required by foo \[cfg2.\]\)%
+          %  new foo/1.0.0 \[cfg2.\] \(required by libbar\)%
+          %  new libbaz/1.0.0 \(required by libbar\)%
+            new libbar/1.0.0
+          %continue\? \[Y/n\] fetched libbaz/1.0.0 \[cfg2.\]%
+          %unpacked libbaz/1.0.0 \[cfg2.\]%
+          %fetched foo/1.0.0 \[cfg2.\]%
+          %unpacked foo/1.0.0 \[cfg2.\]%
+          fetched libbaz/1.0.0
+          unpacked libbaz/1.0.0
+          fetched libbar/1.0.0
+          unpacked libbar/1.0.0
+          %configured libbaz/1.0.0 \[cfg2.\]%
+          %configured foo/1.0.0 \[cfg2.\]%
+          configured libbaz/1.0.0
+          configured libbar/1.0.0
+          %info: .+libbar-1.0.0.+ is up to date%
+          updated libbar/1.0.0
+          EOE
+
+        $pkg_status -r libbar >>/EOO;
+          !libbar configured 1.0.0
+            foo [cfg2/] configured 1.0.0
+              libbaz [cfg2/] configured 1.0.0
+            libbaz configured 1.0.0
+          EOO
+
+        # While at it, make sure that from several available host
+        # configurations the selected package configuration is chosen and we
+        # don't fail with the 'multiple possible host configurations'
+        # diagnostics.
+        #
+        $cfg_create -d cfg3 --type host &cfg3/***;
+        $cfg_link -d cfg cfg3;
+
+        $rep_add $rep/t7b && $rep_fetch;
+
+        $* libbar <'y' 2>>~%EOE%;
+          %  upgrade libbaz/1.1.0 \[cfg2.\] \(required by foo \[cfg2.\]\)%
+          %  upgrade foo/1.1.0 \[cfg2.\] \(required by libbar\)%
+            upgrade libbar/1.1.0
+          %continue\? \[Y/n\] disfigured libbar/1.0.0%
+          %disfigured foo/1.0.0 \[cfg2.\]%
+          %disfigured libbaz/1.0.0 \[cfg2.\]%
+          %fetched libbaz/1.1.0 \[cfg2.\]%
+          %unpacked libbaz/1.1.0 \[cfg2.\]%
+          %fetched foo/1.1.0 \[cfg2.\]%
+          %unpacked foo/1.1.0 \[cfg2.\]%
+          fetched libbar/1.1.0
+          unpacked libbar/1.1.0
+          %configured libbaz/1.1.0 \[cfg2.\]%
+          %configured foo/1.1.0 \[cfg2.\]%
+          configured libbar/1.1.0
+          %info: .+libbar-1.1.0.+ is up to date%
+          updated libbar/1.1.0
+          EOE
+
+        $pkg_status -r libbar >>/EOO;
+          !libbar configured 1.1.0
+            foo [cfg2/] configured 1.1.0
+              libbaz [cfg2/] configured 1.1.0
+            libbaz configured 1.0.0 available 1.1.0
+          EOO
+
+        $* libbar/1.0.0 ?foo/1.0.0 +{ --config-name cfg2 } \
+           ?libbaz/1.0.0 +{ --config-id 1 } <'y' 2>>~%EOE%;
+          %  downgrade libbaz/1.0.0 \[cfg2.\]%
+          %  downgrade foo/1.0.0 \[cfg2.\]%
+            downgrade libbar/1.0.0
+          continue? [Y/n] disfigured libbar/1.1.0
+          %disfigured foo/1.1.0 \[cfg2.\]%
+          %disfigured libbaz/1.1.0 \[cfg2.\]%
+          %fetched libbaz/1.0.0 \[cfg2.\]%
+          %unpacked libbaz/1.0.0 \[cfg2.\]%
+          %fetched foo/1.0.0 \[cfg2.\]%
+          %unpacked foo/1.0.0 \[cfg2.\]%
+          fetched libbar/1.0.0
+          unpacked libbar/1.0.0
+          %configured libbaz/1.0.0 \[cfg2.\]%
+          %configured foo/1.0.0 \[cfg2.\]%
+          configured libbar/1.0.0
+          %info: cfg2.+libbaz-1.0.0.+ is up to date%
+          %info: cfg2.+foo-1.0.0.+ is up to date%
+          %info: cfg.+libbar-1.0.0.+ is up to date%
+          %updated libbaz/1.0.0 \[cfg2.\]%
+          %updated foo/1.0.0 \[cfg2.\]%
+          updated libbar/1.0.0
+          EOE
+
+        $pkg_status -r libbar >>/EOO;
+          !libbar configured !1.0.0 available 1.1.0
+            foo [cfg2/] configured !1.0.0 available 1.1.0
+              libbaz [cfg2/] configured !1.0.0 available 1.1.0
+            libbaz configured 1.0.0 available 1.1.0
+          EOO
+
+        $pkg_drop libbar libbaz
+      }
+
+      : resolve-host-config
+      :
+      {
+        $clone_cfg;
+        cp -pr ../cfg2 ./;
+
+        $cfg_create -d cfg3 --type host &cfg3/***;
+        $cfg_link -d cfg cfg3;
+
+        $* libbar 2>>/~%EOE% != 0;
+          error: multiple possible host configurations for build-time dependency (foo ^1.0.0)
+            info: cfg2/
+            info: cfg3/
+            info: use --config-* to select the configuration
+          %info: while satisfying libbar.1.0.0%
+          EOE
+
+        $* libbar ?foo +{ --config-id 2 } --yes 2>!;
+
+        $pkg_status -r libbar >>/EOO;
+          !libbar configured 1.0.0
+            foo [cfg3/] configured 1.0.0
+              libbaz [cfg3/] configured 1.0.0
+            libbaz configured 1.0.0
+          EOO
+
+        $pkg_drop libbar
+      }
+
+      : 3-configs
+      :
+      {
+        $clone_cfg;
+        cp -pr ../cfg2 ./;
+
+        $cfg_create -d cfg3 --type host &cfg3/***;
+        $cfg_link -d cfg2 cfg3;
+
+        $rep_add -d cfg2 $rep/t7a && $rep_fetch -d cfg2;
+
+        $* -d cfg2 libbaz +{ --config-id 2 } 2>!;
+
+        $* libbar --yes 2>>~%EOE%;
+          %fetched foo/1.0.0 \[cfg2.\]%
+          %unpacked foo/1.0.0 \[cfg2.\]%
+          fetched libbaz/1.0.0
+          unpacked libbaz/1.0.0
+          fetched libbar/1.0.0
+          unpacked libbar/1.0.0
+          %configured foo/1.0.0 \[cfg2.\]%
+          configured libbaz/1.0.0
+          configured libbar/1.0.0
+          %info: .+libbar-1.0.0.+ is up to date%
+          updated libbar/1.0.0
+          EOE
+
+        $pkg_status -r libbar >>/EOO;
+          !libbar configured 1.0.0
+            foo [cfg2/] configured 1.0.0
+              !libbaz [cfg3/] configured 1.0.0
+            libbaz configured 1.0.0
+          EOO
+
+        $pkg_drop libbar
+      }
+    }
+
+    : private-config
+    :
+    {
+      $clone_cfg;
+
+      $* libbar <'y' 2>>~%EOE% &cfg/.bpkg/host/***;
+        %  new libbaz/1.0.0 \[cfg..bpkg.host.\] \(required by foo \[cfg..bpkg.host.\]\)%
+        %  new foo/1.0.0 \[cfg..bpkg.host.\] \(required by libbar\)%
+        %  new libbaz/1.0.0 \(required by libbar\)%
+          new libbar/1.0.0
+        %continue\? \[Y/n\] fetched libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %unpacked libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %fetched foo/1.0.0 \[cfg..bpkg.host.\]%
+        %unpacked foo/1.0.0 \[cfg..bpkg.host.\]%
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        %configured libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %configured foo/1.0.0 \[cfg..bpkg.host.\]%
+        configured libbaz/1.0.0
+        configured libbar/1.0.0
+        %info: .+libbar-1.0.0.+ is up to date%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -r libbar >>/EOO;
+        !libbar configured 1.0.0
+          foo [cfg/.bpkg/host/] configured 1.0.0
+            libbaz [cfg/.bpkg/host/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $rep_add $rep/t7b && $rep_fetch;
+
+      $* libbar <'y' 2>>~%EOE%;
+        %  upgrade libbaz/1.1.0 \[cfg..bpkg.host.\] \(required by foo \[cfg..bpkg.host.\]\)%
+        %  upgrade foo/1.1.0 \[cfg..bpkg.host.\] \(required by libbar\)%
+          upgrade libbar/1.1.0
+        %continue\? \[Y/n\] disfigured libbar/1.0.0%
+        %disfigured foo/1.0.0 \[cfg..bpkg.host.\]%
+        %disfigured libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %fetched libbaz/1.1.0 \[cfg..bpkg.host.\]%
+        %unpacked libbaz/1.1.0 \[cfg..bpkg.host.\]%
+        %fetched foo/1.1.0 \[cfg..bpkg.host.\]%
+        %unpacked foo/1.1.0 \[cfg..bpkg.host.\]%
+        fetched libbar/1.1.0
+        unpacked libbar/1.1.0
+        %configured libbaz/1.1.0 \[cfg..bpkg.host.\]%
+        %configured foo/1.1.0 \[cfg..bpkg.host.\]%
+        configured libbar/1.1.0
+        %info: .+libbar-1.1.0.+ is up to date%
+        updated libbar/1.1.0
+        EOE
+
+      $pkg_status -r libbar >>/EOO;
+        !libbar configured 1.1.0
+          foo [cfg/.bpkg/host/] configured 1.1.0
+            libbaz [cfg/.bpkg/host/] configured 1.1.0
+          libbaz configured 1.0.0 available 1.1.0
+        EOO
+
+      $pkg_drop libbar
+    }
+
+    : self-hosted-config
+    :
+    {
+      $cfg_create -d cfg --type host &cfg/***;
+      $rep_add $rep/t7a && $rep_fetch;
+
+      $* libbar <'y' 2>>~%EOE%;
+          new libbaz/1.0.0 (required by foo libbar)
+          new foo/1.0.0 (required by libbar)
+          new libbar/1.0.0
+        continue? [Y/n] fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched foo/1.0.0
+        unpacked foo/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        configured libbaz/1.0.0
+        configured foo/1.0.0
+        configured libbar/1.0.0
+        %info: .+libbar-1.0.0.+ is up to date%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -r libbar >>/EOO;
+        !libbar configured 1.0.0
+          foo configured 1.0.0
+            libbaz configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $rep_add $rep/t7b && $rep_fetch;
+
+      $* libbar <'y' 2>>~%EOE%;
+          upgrade libbaz/1.1.0 (required by foo libbar)
+          upgrade foo/1.1.0 (required by libbar)
+          upgrade libbar/1.1.0
+        continue? [Y/n] disfigured libbar/1.0.0
+        disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        fetched libbaz/1.1.0
+        unpacked libbaz/1.1.0
+        fetched foo/1.1.0
+        unpacked foo/1.1.0
+        fetched libbar/1.1.0
+        unpacked libbar/1.1.0
+        configured libbaz/1.1.0
+        configured foo/1.1.0
+        configured libbar/1.1.0
+        %info: .+libbar-1.1.0.+ is up to date%
+        updated libbar/1.1.0
+        EOE
+
+      $pkg_status -r libbar >>/EOO;
+        !libbar configured 1.1.0
+          foo configured 1.1.0
+            libbaz configured 1.1.0
+          libbaz configured 1.1.0
+        EOO
+
+      $pkg_drop libbar
+    }
+  }
+
+  : verify-dependencies
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t7a && $rep_fetch
+
+    : fail
+    :
+    {
+      $cfg_create -d cfg2 &cfg2/***;
+      $rep_add -d cfg2 $rep/t7a && $rep_fetch -d cfg2;
+
+      $cfg_create -d cfg3 &cfg3/***;
+      $rep_add -d cfg3 $rep/t7a && $rep_fetch -d cfg3;
+
+      $* -d cfg2 --yes libbar 2>!;
+      $* -d cfg3 --yes libbox 2>!;
+
+      $clone_cfg;
+      $cfg_link -d cfg cfg2;
+      $cfg_link -d cfg cfg3;
+
+      $* libfix --yes 2>>~%EOE% != 0
+        error: package libbaz indirectly required by libfix/1.0.0 is configured in multiple configurations
+        %  info: libbaz/1.0.0 \[cfg3.\]%
+        %  info: libbaz/1.0.0 \[cfg2.\]%
+        EOE
+    }
+
+    : succeed
+    :
+    {
+      $cfg_create -d cfg2 &cfg2/***;
+      $rep_add -d cfg2 $rep/t7b && $rep_fetch -d cfg2;
+
+      $cfg_create -d cfg3 &cfg3/***;
+      $rep_add -d cfg3 $rep/t7b && $rep_fetch -d cfg3;
+
+      $* -d cfg2 --yes libbar 2>!;
+      $* -d cfg3 --yes libbox 2>!;
+
+      $clone_cfg;
+      $cfg_link -d cfg cfg2;
+      $cfg_link -d cfg cfg3;
+
+      $* libfix --yes 2>>~%EOE%;
+        fetched libfax/1.0.0
+        unpacked libfax/1.0.0
+        fetched libfix/1.0.0
+        unpacked libfix/1.0.0
+        configured libfax/1.0.0
+        configured libfix/1.0.0
+        %info: .+libfix-1.0.0.+ is up to date%
+        updated libfix/1.0.0
+        EOE
+
+      $pkg_drop libfix
+    }
+  }
+
+  : change-config
+  :
+  {
+    : copy
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbaz --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 libbaz +{ --config-name t2 } 2>>~%EOE%;
+        %fetched libbaz/1.0.0 \[t2.\]%
+        %unpacked libbaz/1.0.0 \[t2.\]%
+        %configured libbaz/1.0.0 \[t2.\]%
+        %info: t2.+libbaz-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[t2.\]%
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbaz configured 1.0.0
+        !libbaz [t2/] configured 1.0.0
+        EOO
+    }
+
+    : copy-unhold
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbaz --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 ?libbaz +{ --config-name t2 };
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbaz configured 1.0.0
+        EOO
+    }
+
+    : copy-point
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbaz --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 foo libbaz +{ --config-name t2 } 2>>~%EOE%;
+        %fetched libbaz/1.0.0 \[t2.\]%
+        %unpacked libbaz/1.0.0 \[t2.\]%
+        fetched foo/1.0.0
+        unpacked foo/1.0.0
+        %configured libbaz/1.0.0 \[t2.\]%
+        configured foo/1.0.0
+        %info: t2.+libbaz-1.0.0.+ is up to date%
+        %info: t1.+foo-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[t2.\]%
+        updated foo/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbaz configured 1.0.0
+        !foo configured 1.0.0
+          !libbaz [t2/] configured 1.0.0
+        !libbaz [t2/] configured 1.0.0
+        EOO
+    }
+
+    : copy-unhold-point
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbaz --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 foo ?libbaz +{ --config-name t2 } 2>>~%EOE%;
+        %fetched libbaz/1.0.0 \[t2.\]%
+        %unpacked libbaz/1.0.0 \[t2.\]%
+        fetched foo/1.0.0
+        unpacked foo/1.0.0
+        %configured libbaz/1.0.0 \[t2.\]%
+        configured foo/1.0.0
+        %info: t2.+libbaz-1.0.0.+ is up to date%
+        %info: t1.+foo-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[t2.\]%
+        updated foo/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbaz configured 1.0.0
+        !foo configured 1.0.0
+          libbaz [t2/] configured 1.0.0
+        EOO
+    }
+
+    : copy-repoint
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d t1 h1;
+      $cfg_link -d t1 h2;
+
+      $cfg_link -d t2 h1;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+      $rep_add -d t2 $rep/t7a && $rep_fetch -d t2;
+
+      $* -d t1 libbar ?foo +{ --config-name h1 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[h1.\] \(required by foo \[h1.\]\)%
+        %  new foo/1.0.0 \[h1.\]%
+          new libbaz/1.0.0 (required by libbar)
+          new libbar/1.0.0
+        %continue\? \[Y/n\] fetched libbaz/1.0.0 \[h1.\]%
+        %unpacked libbaz/1.0.0 \[h1.\]%
+        %fetched foo/1.0.0 \[h1.\]%
+        %unpacked foo/1.0.0 \[h1.\]%
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        %configured libbaz/1.0.0 \[h1.\]%
+        %configured foo/1.0.0 \[h1.\]%
+        configured libbaz/1.0.0
+        configured libbar/1.0.0
+        %info: h1.+foo-1.0.0.+ is up to date%
+        %info: t1.+libbar-1.0.0.+ is up to date%
+        %updated foo/1.0.0 \[h1.\]%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo [h1/] configured 1.0.0
+            libbaz [h1/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d t2 libbox ?foo +{ --config-name h1 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  update foo/1.0.0 \[h1.\]%
+          new libbaz/1.0.0 (required by libbox)
+          new libbox/1.0.0
+        continue? [Y/n] fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched libbox/1.0.0
+        unpacked libbox/1.0.0
+        configured libbaz/1.0.0
+        configured libbox/1.0.0
+        %info: h1.+foo-1.0.0.+ is up to date%
+        %info: t2.+libbox-1.0.0.+ is up to date%
+        %updated foo/1.0.0 \[h1.\]%
+        updated libbox/1.0.0
+        EOE
+
+      $pkg_status -d t2 -r >>/EOO;
+        !libbox configured 1.0.0
+          foo [h1/] configured 1.0.0
+            libbaz [h1/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 ?foo +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  new libbaz/1.0.0 \[h2.\] \(required by foo \[h2.\]\)%
+        %  new foo/1.0.0 \[h2.\]%
+        %  reconfigure libbar/1.0.0 \(dependent of foo \[h2.\]\)%
+        continue? [Y/n] update dependent packages? [Y/n] disfigured libbar/1.0.0
+        %fetched libbaz/1.0.0 \[h2.\]%
+        %unpacked libbaz/1.0.0 \[h2.\]%
+        %fetched foo/1.0.0 \[h2.\]%
+        %unpacked foo/1.0.0 \[h2.\]%
+        %configured libbaz/1.0.0 \[h2.\]%
+        %configured foo/1.0.0 \[h2.\]%
+        configured libbar/1.0.0
+        %info: h2.+foo-1.0.0.+ is up to date%
+        %info: t1.+libbar-1.0.0.+ is up to date%
+        %updated foo/1.0.0 \[h2.\]%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo [h2/] configured 1.0.0
+            libbaz [h2/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $pkg_status -d t2 -r >>/EOO
+        !libbox configured 1.0.0
+          foo [h1/] configured 1.0.0
+            libbaz [h1/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+    }
+
+    : copy-repoint-drop
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 foo --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 libbaz +{ --config-name t2 } <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  new libbaz/1.0.0 \[t2.\]%
+          drop libbaz/1.0.0 (unused)
+        %  reconfigure foo/1.0.0 \(dependent of libbaz \[t2.\]\)%
+        continue? [Y/n] update dependent packages? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.0.0 \[t2.\]%
+        %unpacked libbaz/1.0.0 \[t2.\]%
+        purged libbaz/1.0.0
+        %configured libbaz/1.0.0 \[t2.\]%
+        configured foo/1.0.0
+        %info: t2.+libbaz-1.0.0.+ is up to date%
+        %info: t1.+foo-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[t2.\]%
+        updated foo/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !foo configured 1.0.0
+          !libbaz [t2/] configured 1.0.0
+        !libbaz [t2/] configured 1.0.0
+        EOO
+    }
+
+    : drop-repointed
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 foo --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d t1 ?foo libbaz +{ --config-name t2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[t2.\]%
+          drop libbaz/1.0.0 (unused)
+          drop foo/1.0.0 (unused)
+        continue? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.0.0 \[t2.\]%
+        %unpacked libbaz/1.0.0 \[t2.\]%
+        purged libbaz/1.0.0
+        purged foo/1.0.0
+        %configured libbaz/1.0.0 \[t2.\]%
+        %info: t2.+libbaz-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[t2.\]%
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbaz [t2/] configured 1.0.0
+        EOO
+    }
+
+    : dependency-repointed
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 foo --yes 2>!;
+
+      $pkg_status -d h1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d h1 libbar libbaz +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[h2.\]%
+          drop libbaz/1.0.0 (unused)
+          reconfigure/update foo/1.0.0 (required by libbar)
+          new libbar/1.0.0
+        continue? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.0.0 \[h2.\]%
+        %unpacked libbaz/1.0.0 \[h2.\]%
+        purged libbaz/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        %configured libbaz/1.0.0 \[h2.\]%
+        configured foo/1.0.0
+        configured libbar/1.0.0
+        %info: h2.+libbaz-1.0.0.+ is up to date%
+        %info: h1.+libbar-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[h2.\]%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO
+        !foo configured 1.0.0
+          !libbaz [h2/] configured 1.0.0
+        !libbar configured 1.0.0
+          !foo configured 1.0.0
+            !libbaz [h2/] configured 1.0.0
+          !libbaz [h2/] configured 1.0.0
+        !libbaz [h2/] configured 1.0.0
+        EOO
+    }
+
+    : dependency-repointed-system
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 foo --yes 2>!;
+
+      $pkg_status -d h1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d h1 libbar '?sys:foo/1.2.0' ?libbaz +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[h2.\]%
+          drop libbaz/1.0.0 (unused)
+          reconfigure/unhold sys:foo/1.2.0
+          new libbar/1.0.0
+        continue? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.0.0 \[h2.\]%
+        %unpacked libbaz/1.0.0 \[h2.\]%
+        purged libbaz/1.0.0
+        purged foo/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        %configured libbaz/1.0.0 \[h2.\]%
+        configured sys:foo/1.2.0
+        configured libbar/1.0.0
+        %info: h2.+libbaz-1.0.0.+ is up to date%
+        %info: h1.+libbar-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[h2.\]%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo configured,system !1.2.0
+          libbaz [h2/] configured 1.0.0
+        EOO
+
+      $* -d h1 ?foo ?libbaz <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  drop libbaz/1.0.0 \[h2.\] \(unused\)%
+          new libbaz/1.0.0
+          downgrade foo/1.0.0
+          reconfigure libbar/1.0.0 (dependent of libbaz)
+        continue? [Y/n] update dependent packages? [Y/n] disfigured libbar/1.0.0
+        purged foo/1.2.0
+        %disfigured libbaz/1.0.0 \[h2.\]%
+        %purged libbaz/1.0.0 \[h2.\]%
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched foo/1.0.0
+        unpacked foo/1.0.0
+        configured libbaz/1.0.0
+        configured foo/1.0.0
+        configured libbar/1.0.0
+        %info: h1.+libbaz-1.0.0.+ is up to date%
+        %info: h1.+foo-1.0.0.+ is up to date%
+        %info: h1.+libbar-1.0.0.+ is up to date%
+        updated libbaz/1.0.0
+        updated foo/1.0.0
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO
+        !libbar configured 1.0.0
+          foo configured 1.0.0
+            libbaz configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+    }
+
+    : orphan-repointed
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h1 $rep/t7b && $rep_fetch -d h1;
+
+      $* -d h1 foo --yes 2>!;
+
+      $rep_remove -d h1 $rep/t7b;
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 libbaz +{ --config-name h2 } 2>>EOE != 0
+        error: package foo/1.1.0 is orphaned
+          info: explicitly upgrade it to a new version
+        info: while satisfying foo/1.1.0
+        EOE
+    }
+
+    : unhold-repointed
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 foo --yes 2>!;
+
+      $pkg_status -d h1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $* -d h1 libbar ?foo libbaz +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[h2.\]%
+          drop libbaz/1.0.0 (unused)
+          reconfigure/update/unhold foo/1.0.0
+          new libbar/1.0.0
+        continue? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.0.0 \[h2.\]%
+        %unpacked libbaz/1.0.0 \[h2.\]%
+        purged libbaz/1.0.0
+        fetched libbar/1.0.0
+        unpacked libbar/1.0.0
+        %configured libbaz/1.0.0 \[h2.\]%
+        configured foo/1.0.0
+        configured libbar/1.0.0
+        %info: h2.+libbaz-1.0.0.+ is up to date%
+        %info: h1.+foo-1.0.0.+ is up to date%
+        %info: h1.+libbar-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[h2.\]%
+        updated foo/1.0.0
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO
+        !libbar configured 1.0.0
+          foo configured 1.0.0
+            !libbaz [h2/] configured 1.0.0
+          !libbaz [h2/] configured 1.0.0
+        !libbaz [h2/] configured 1.0.0
+        EOO
+    }
+
+    : satisfy
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h2 $rep/t7b && $rep_fetch -d h2;
+      $* -d h2 foo --yes 2>!;
+
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 foo ?libbaz 2>>~%EOE%;
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched foo/1.0.0
+        unpacked foo/1.0.0
+        configured libbaz/1.0.0
+        configured foo/1.0.0
+        %info: h1.+libbaz-1.0.0.+ is up to date%
+        %info: h1.+foo-1.0.0.+ is up to date%
+        updated libbaz/1.0.0
+        updated foo/1.0.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO;
+        !foo configured 1.0.0
+          libbaz configured 1.0.0
+        !foo [h2/] configured 1.1.0
+          libbaz [h2/] configured 1.1.0
+        EOO
+
+      $* -d h1 ?libbaz/1.0.0 +{ --config-name h2 } 2>>~%EOE% != 0;
+        %error: unable to downgrade package libbaz/1.1.0 \[h2.\] to 1.0.0%
+        %  info: because package foo \[h2.\] depends on \(libbaz \^1.1.0\)%
+          info: explicitly request up/downgrade of package foo
+          info: or explicitly specify package libbaz version to manually satisfy these constraints
+        EOE
+
+      $* -d h1 ?libbaz +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        n
+        EOI
+        %  update libbaz/1.1.0 \[h2.\]%
+          drop libbaz/1.0.0 (unused)
+        %  reconfigure foo/1.0.0 \(dependent of libbaz \[h2.\]\)%
+        continue? [Y/n] update dependent packages? [Y/n] disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        purged libbaz/1.0.0
+        configured foo/1.0.0
+        %info: h2.+libbaz-1.1.0.+ is up to date%
+        %updated libbaz/1.1.0 \[h2.\]%
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO
+        !foo configured 1.0.0
+          libbaz [h2/] configured 1.1.0
+        !foo [h2/] configured 1.1.0
+          libbaz [h2/] configured 1.1.0
+        EOO
+    }
+
+    : upgrade-repointed
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbar --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo [t1/.bpkg/host/] configured 1.0.0
+            libbaz [t1/.bpkg/host/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+
+      $cfg_link -d t1 h1 2>!;
+
+      $rep_add -d t1 $rep/t7b && $rep_fetch -d t1;
+
+      $* -d t1 libbar ?foo +{ --config-name h1 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.1.0 \[h1.\] \(required by foo \[h1.\]\)%
+        %  new foo/1.1.0 \[h1.\]%
+        %  drop libbaz/1.0.0 \[t1..bpkg.host.\] \(unused\)%
+        %  drop foo/1.0.0 \[t1..bpkg.host.\] \(unused\)%
+          upgrade libbar/1.1.0
+        continue? [Y/n] disfigured libbar/1.0.0
+        %disfigured foo/1.0.0 \[t1..bpkg.host.\]%
+        %disfigured libbaz/1.0.0 \[t1..bpkg.host.\]%
+        %fetched libbaz/1.1.0 \[h1.\]%
+        %unpacked libbaz/1.1.0 \[h1.\]%
+        %fetched foo/1.1.0 \[h1.\]%
+        %unpacked foo/1.1.0 \[h1.\]%
+        %purged libbaz/1.0.0 \[t1..bpkg.host.\]%
+        %purged foo/1.0.0 \[t1..bpkg.host.\]%
+        fetched libbar/1.1.0
+        unpacked libbar/1.1.0
+        %configured libbaz/1.1.0 \[h1.\]%
+        %configured foo/1.1.0 \[h1.\]%
+        configured libbar/1.1.0
+        %info: h1.+foo-1.1.0.+ is up to date%
+        %info: t1.+libbar-1.1.0.+ is up to date%
+        %updated foo/1.1.0 \[h1.\]%
+        updated libbar/1.1.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbar configured 1.1.0
+          foo [h1/] configured 1.1.0
+            libbaz [h1/] configured 1.1.0
+          libbaz configured 1.0.0 available 1.1.0
+        EOO
+    }
+
+    : upgrade-repointed-dependency
+    :
+    {
+      $cfg_create -d h1 --type host --name h1 &h1/***;
+      $cfg_create -d h2 --type host --name h2 &h2/***;
+
+      $cfg_link -d h1 h2;
+
+      $rep_add -d h1 $rep/t7a && $rep_fetch -d h1;
+
+      $* -d h1 libbar --yes 2>!;
+
+      $pkg_status -d h1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo configured 1.0.0
+            libbaz configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $rep_add -d h1 $rep/t7b && $rep_fetch -d h1;
+
+      $* -d h1 libbar ?foo ?libbaz +{ --config-name h2 } <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  new libbaz/1.1.0 \[h2.\]%
+          drop libbaz/1.0.0 (unused)
+          upgrade foo/1.1.0
+          upgrade libbar/1.1.0
+        continue? [Y/n] disfigured libbar/1.0.0
+        disfigured foo/1.0.0
+        disfigured libbaz/1.0.0
+        %fetched libbaz/1.1.0 \[h2.\]%
+        %unpacked libbaz/1.1.0 \[h2.\]%
+        purged libbaz/1.0.0
+        fetched foo/1.1.0
+        unpacked foo/1.1.0
+        fetched libbar/1.1.0
+        unpacked libbar/1.1.0
+        %configured libbaz/1.1.0 \[h2.\]%
+        configured foo/1.1.0
+        configured libbar/1.1.0
+        %info: h2.+libbaz-1.1.0.+ is up to date%
+        %info: h1.+foo-1.1.0.+ is up to date%
+        %info: h1.+libbar-1.1.0.+ is up to date%
+        %updated libbaz/1.1.0 \[h2.\]%
+        updated foo/1.1.0
+        updated libbar/1.1.0
+        EOE
+
+      $pkg_status -d h1 -r >>/EOO
+        !libbar configured 1.1.0
+          foo configured 1.1.0
+            libbaz [h2/] configured 1.1.0
+          libbaz [h2/] configured 1.1.0
+        EOO
+    }
+
+    : upgrade-prerequisite-replacement
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbar --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo [t1/.bpkg/host/] configured 1.0.0
+            libbaz [t1/.bpkg/host/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $rep_add -d t2 $rep/t7a && $rep_fetch -d t2;
+
+      $* -d t2 libbaz --yes 2>!;
+
+      $cfg_link -d t1 t2 2>!;
+
+      $rep_add -d t1 $rep/t7b && $rep_fetch -d t1;
+
+      $* -d t1 libbaz +{ --config-name t2 } <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  upgrade libbaz/1.1.0 \[t2.\]%
+          drop libbaz/1.0.0 (unused)
+        %  reconfigure libbar/1.0.0 \(dependent of libbaz \[t2.\]\)%
+        continue? [Y/n] update dependent packages? [Y/n] disfigured libbar/1.0.0
+        disfigured libbaz/1.0.0
+        %disfigured libbaz/1.0.0 \[t2.\]%
+        %fetched libbaz/1.1.0 \[t2.\]%
+        %unpacked libbaz/1.1.0 \[t2.\]%
+        purged libbaz/1.0.0
+        %configured libbaz/1.1.0 \[t2.\]%
+        configured libbar/1.0.0
+        %info: t2.+libbaz-1.1.0.+ is up to date%
+        %info: t1.+libbar-1.0.0.+ is up to date%
+        %updated libbaz/1.1.0 \[t2.\]%
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbar configured 1.0.0 available 1.1.0
+          foo [t1/.bpkg/host/] configured 1.0.0 available 1.1.0
+            libbaz [t1/.bpkg/host/] configured 1.0.0 available 1.1.0
+          !libbaz [t2/] configured 1.1.0
+        !libbaz [t2/] configured 1.1.0
+        EOO
+    }
+
+    : copy-upgrade-dependency-tree
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libbar --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libbar configured 1.0.0
+          foo [t1/.bpkg/host/] configured 1.0.0
+            libbaz [t1/.bpkg/host/] configured 1.0.0
+          libbaz configured 1.0.0
+        EOO
+
+      $cfg_create -d t2 --name t2 &t2/***;
+
+      $cfg_link -d t1 t2 2>!;
+
+      $rep_add -d t1 $rep/t7b && $rep_fetch -d t1;
+
+      $* -d t1 libbar +{ --config-name t2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.1.0 \[t2..bpkg.host.\] \(required by foo \[t2..bpkg.host.\]\)%
+        %  new foo/1.1.0 \[t2..bpkg.host.\] \(required by libbar \[t2.\]\)%
+        %  new libbaz/1.1.0 \[t2.\] \(required by libbar \[t2.\]\)%
+        %  new libbar/1.1.0 \[t2.\]%
+        %continue\? \[Y/n\] fetched libbaz/1.1.0 \[t2..bpkg.host.\]%
+        %unpacked libbaz/1.1.0 \[t2..bpkg.host.\]%
+        %fetched foo/1.1.0 \[t2..bpkg.host.\]%
+        %unpacked foo/1.1.0 \[t2..bpkg.host.\]%
+        %fetched libbaz/1.1.0 \[t2.\]%
+        %unpacked libbaz/1.1.0 \[t2.\]%
+        %fetched libbar/1.1.0 \[t2.\]%
+        %unpacked libbar/1.1.0 \[t2.\]%
+        %configured libbaz/1.1.0 \[t2..bpkg.host.\]%
+        %configured foo/1.1.0 \[t2..bpkg.host.\]%
+        %configured libbaz/1.1.0 \[t2.\]%
+        %configured libbar/1.1.0 \[t2.\]%
+        %info: t2.+libbar-1.1.0.+ is up to date%
+        %updated libbar/1.1.0 \[t2.\]%
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libbar configured 1.0.0 available 1.1.0
+          foo [t1/.bpkg/host/] configured 1.0.0 available 1.1.0
+            libbaz [t1/.bpkg/host/] configured 1.0.0 available 1.1.0
+          libbaz configured 1.0.0 available 1.1.0
+        !libbar [t2/] configured 1.1.0
+          foo [t2/.bpkg/host/] configured 1.1.0
+            libbaz [t2/.bpkg/host/] configured 1.1.0
+          libbaz [t2/] configured 1.1.0
+        EOO
+    }
+
+    : repointed-dependent-indirect-dependency-upgrade
+    :
+    {
+      $cfg_create -d t1 --name t1 &t1/***;
+      $cfg_create -d t2 --name t2 &t2/***;
+      $cfg_create -d h1 --name h1 --type host &h1/***;
+
+      $cfg_link -d t1 t2 2>!;
+      $cfg_link -d t1 h1 2>!;
+      $cfg_link -d t2 h1 2>!;
+
+      $rep_add -d t1 $rep/t7a && $rep_fetch -d t1;
+
+      $* -d t1 libfix --yes 2>!;
+
+      $pkg_status -d t1 -r >>/EOO;
+        !libfix configured 1.0.0
+          libbar configured 1.0.0
+            foo [h1/] configured 1.0.0
+              libbaz [h1/] configured 1.0.0
+            libbaz configured 1.0.0
+          libbox configured 1.0.0
+            foo [h1/] configured 1.0.0
+              libbaz [h1/] configured 1.0.0
+            libbaz configured 1.0.0
+          libfax configured 1.0.0
+        EOO
+
+      $rep_add -d t1 $rep/t7b && $rep_fetch -d t1;
+
+      $* -d t1 libfix libfax +{ --config-name t2 } foo +{ --config-name h1 } <<EOI 2>>~%EOE%;
+        y
+        y
+        EOI
+        %  new libfax/1.0.0 \[t2.\]%
+        %  upgrade libbaz/1.1.0 \[h1.\] \(required by foo \[h1.\]\)%
+        %  upgrade foo/1.1.0 \[h1.\]%
+        %  reconfigure libbox \(dependent of foo \[h1.\]\)%
+        %  reconfigure libbar \(dependent of foo \[h1.\]\)%
+        %  drop libfax/1.0.0 \(unused\)%
+          reconfigure/update libfix/1.0.0
+        continue? [Y/n] update dependent packages? [Y/n] disfigured libfix/1.0.0
+        disfigured libfax/1.0.0
+        disfigured libbar/1.0.0
+        disfigured libbox/1.0.0
+        %disfigured foo/1.0.0 \[h1.\]%
+        %disfigured libbaz/1.0.0 \[h1.\]%
+        %fetched libfax/1.0.0 \[t2.\]%
+        %unpacked libfax/1.0.0 \[t2.\]%
+        %fetched libbaz/1.1.0 \[h1.\]%
+        %unpacked libbaz/1.1.0 \[h1.\]%
+        %fetched foo/1.1.0 \[h1.\]%
+        %unpacked foo/1.1.0 \[h1.\]%
+        purged libfax/1.0.0
+        %configured libfax/1.0.0 \[t2.\]%
+        %configured libbaz/1.1.0 \[h1.\]%
+        %configured foo/1.1.0 \[h1.\]%
+        configured libbox/1.0.0
+        configured libbar/1.0.0
+        configured libfix/1.0.0
+        %info: t2.+libfax-1.0.0.+ is up to date%
+        %info: h1.+foo-1.1.0.+ is up to date%
+        %info: t1.+libfix-1.0.0.+ is up to date%
+        %info: t1.+libbox-1.0.0.+ is up to date%
+        %info: t1.+libbar-1.0.0.+ is up to date%
+        %updated libfax/1.0.0 \[t2.\]%
+        %updated foo/1.1.0 \[h1.\]%
+        updated libfix/1.0.0
+        updated libbox/1.0.0
+        updated libbar/1.0.0
+        EOE
+
+      $pkg_status -d t1 -r >>/EOO
+        !libfix configured 1.0.0
+          libbar configured 1.0.0 available 1.1.0
+            !foo [h1/] configured 1.1.0
+              libbaz [h1/] configured 1.1.0
+            libbaz configured 1.0.0 available 1.1.0
+          libbox configured 1.0.0 available 1.1.0
+            !foo [h1/] configured 1.1.0
+              libbaz [h1/] configured 1.1.0
+            libbaz configured 1.0.0 available 1.1.0
+          !libfax [t2/] configured 1.0.0
+        !libfax [t2/] configured 1.0.0
+        !foo [h1/] configured 1.1.0
+          libbaz [h1/] configured 1.1.0
+        EOO
+    }
+  }
+
+  : build2-module-dep
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t7a && $rep_fetch
+
+    : private-config
+    :
+    {
+      $clone_cfg;
+
+      $* libbiz <<EOI 2>>~%EOE% &cfg/.bpkg/build2/*** &cfg/.bpkg/host/***;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[cfg..bpkg.host.\] \(required by foo \[cfg..bpkg.host.\]\)%
+        %  new foo/1.0.0 \[cfg..bpkg.host.\] \(required by libbiz\)%
+        %  new libbaz/1.0.0 \[cfg..bpkg.build2..bpkg.host.\] \(required by foo \[cfg..bpkg.build2..bpkg.host.\]\)%
+        %  new foo/1.0.0 \[cfg..bpkg.build2..bpkg.host.\] \(required by libbuild2-foo \[cfg..bpkg.build2.\]\)%
+        %  new libbuild2-bar/1.0.0 \[cfg..bpkg.build2.\] \(required by libbuild2-foo \[cfg..bpkg.build2.\]\)%
+        %  new libbaz/1.0.0 \[cfg..bpkg.build2.\] \(required by libbuild2-foo \[cfg..bpkg.build2.\]\)%
+        %  new libbuild2-foo/1.0.0 \[cfg..bpkg.build2.\] \(required by libbiz\)%
+          new libbaz/1.0.0 (required by libbiz)
+          new libbiz/1.0.0
+        %continue\? \[Y/n\] fetched libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %unpacked libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %fetched foo/1.0.0 \[cfg..bpkg.host.\]%
+        %unpacked foo/1.0.0 \[cfg..bpkg.host.\]%
+        %fetched libbaz/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %unpacked libbaz/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %fetched foo/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %unpacked foo/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %fetched libbuild2-bar/1.0.0 \[cfg..bpkg.build2.\]%
+        %unpacked libbuild2-bar/1.0.0 \[cfg..bpkg.build2.\]%
+        %fetched libbaz/1.0.0 \[cfg..bpkg.build2.\]%
+        %unpacked libbaz/1.0.0 \[cfg..bpkg.build2.\]%
+        %fetched libbuild2-foo/1.0.0 \[cfg..bpkg.build2.\]%
+        %unpacked libbuild2-foo/1.0.0 \[cfg..bpkg.build2.\]%
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched libbiz/1.0.0
+        unpacked libbiz/1.0.0
+        %configured libbaz/1.0.0 \[cfg..bpkg.host.\]%
+        %configured foo/1.0.0 \[cfg..bpkg.host.\]%
+        %configured libbaz/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %configured foo/1.0.0 \[cfg..bpkg.build2..bpkg.host.\]%
+        %configured libbuild2-bar/1.0.0 \[cfg..bpkg.build2.\]%
+        %configured libbaz/1.0.0 \[cfg..bpkg.build2.\]%
+        %configured libbuild2-foo/1.0.0 \[cfg..bpkg.build2.\]%
+        configured libbaz/1.0.0
+        configured libbiz/1.0.0
+        %info: cfg.+libbiz-1.0.0.+ is up to date%
+        updated libbiz/1.0.0
+        EOE
+
+      $pkg_status -d cfg -r >>/EOO;
+        !libbiz configured 1.0.0
+          foo [cfg/.bpkg/host/] configured 1.0.0
+            libbaz [cfg/.bpkg/host/] configured 1.0.0
+          libbaz configured 1.0.0
+          libbuild2-foo [cfg/.bpkg/build2/] configured 1.0.0
+            foo [cfg/.bpkg/build2/.bpkg/host/] configured 1.0.0
+              libbaz [cfg/.bpkg/build2/.bpkg/host/] configured 1.0.0
+            libbaz [cfg/.bpkg/build2/] configured 1.0.0
+            libbuild2-bar [cfg/.bpkg/build2/] configured 1.0.0
+        EOO
+
+      $pkg_drop libbiz
+    }
+
+    : external-config
+    :
+    {
+      $clone_cfg;
+
+      $cfg_create -d cfg2 --type build2 --name cfg2 &cfg2/***;
+      $cfg_link -d cfg cfg2;
+
+      $cfg_create -d cfg3 --type host --name cfg3 &cfg3/***;
+      $cfg_link -d cfg  cfg3;
+      $cfg_link -d cfg2 cfg3;
+
+      $* libbiz <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[cfg3.\] \(required by foo \[cfg3.\]\)%
+        %  new foo/1.0.0 \[cfg3.\] \(required by libbiz libbuild2-foo \[cfg2.\]\)%
+        %  new libbuild2-bar/1.0.0 \[cfg2.\] \(required by libbuild2-foo \[cfg2.\]\)%
+        %  new libbaz/1.0.0 \[cfg2.\] \(required by libbuild2-foo \[cfg2.\]\)%
+        %  new libbuild2-foo/1.0.0 \[cfg2.\] \(required by libbiz\)%
+          new libbaz/1.0.0 (required by libbiz)
+          new libbiz/1.0.0
+        %continue\? \[Y/n\] fetched libbaz/1.0.0 \[cfg3.\]%
+        %unpacked libbaz/1.0.0 \[cfg3.\]%
+        %fetched foo/1.0.0 \[cfg3.\]%
+        %unpacked foo/1.0.0 \[cfg3.\]%
+        %fetched libbuild2-bar/1.0.0 \[cfg2.\]%
+        %unpacked libbuild2-bar/1.0.0 \[cfg2.\]%
+        %fetched libbaz/1.0.0 \[cfg2.\]%
+        %unpacked libbaz/1.0.0 \[cfg2.\]%
+        %fetched libbuild2-foo/1.0.0 \[cfg2.\]%
+        %unpacked libbuild2-foo/1.0.0 \[cfg2.\]%
+        fetched libbaz/1.0.0
+        unpacked libbaz/1.0.0
+        fetched libbiz/1.0.0
+        unpacked libbiz/1.0.0
+        %configured libbaz/1.0.0 \[cfg3.\]%
+        %configured foo/1.0.0 \[cfg3.\]%
+        %configured libbuild2-bar/1.0.0 \[cfg2.\]%
+        %configured libbaz/1.0.0 \[cfg2.\]%
+        %configured libbuild2-foo/1.0.0 \[cfg2.\]%
+        configured libbaz/1.0.0
+        configured libbiz/1.0.0
+        %info: cfg.+libbiz-1.0.0.+ is up to date%
+        updated libbiz/1.0.0
+        EOE
+
+      $pkg_status -d cfg -r >>/EOO;
+        !libbiz configured 1.0.0
+          foo [cfg3/] configured 1.0.0
+            libbaz [cfg3/] configured 1.0.0
+          libbaz configured 1.0.0
+          libbuild2-foo [cfg2/] configured 1.0.0
+            foo [cfg3/] configured 1.0.0
+              libbaz [cfg3/] configured 1.0.0
+            libbaz [cfg2/] configured 1.0.0
+            libbuild2-bar [cfg2/] configured 1.0.0
+        EOO
+
+      $pkg_drop libbiz
+    }
+
+    : build2-config
+    :
+    {
+      $cfg_create -d cfg --type build2 &cfg/***;
+      $rep_add $rep/t7a && $rep_fetch;
+
+      $* libbiz 2>>~%EOE% != 0;
+        %error: unable to build build system module libbuild2-foo in its dependent package configuration cfg.%
+          info: use --config-* to select suitable configuration
+        info: while satisfying libbiz/1.0.0
+        EOE
+
+      $cfg_create -d cfg2 --type build2 --name cfg2 &cfg2/***;
+      $cfg_link -d cfg cfg2;
+
+      $cfg_create -d cfg3 --type host --name cfg3 &cfg3/***;
+      $cfg_link -d cfg  cfg3;
+      $cfg_link -d cfg2 cfg3;
+
+      $* libbiz ?libbuild2-foo +{ --config-name cfg2 } \
+                ?libbaz +{ --config-name cfg2 } <<EOI 2>>~%EOE%;
+        y
+        EOI
+        %  new libbaz/1.0.0 \[cfg3.\] \(required by foo \[cfg3.\]\)%
+        %  new foo/1.0.0 \[cfg3.\] \(required by libbiz libbuild2-foo \[cfg2.\]\)%
+        %  new libbuild2-bar/1.0.0 \[cfg2.\] \(required by libbuild2-foo \[cfg2.\]\)%
+        %  new libbaz/1.0.0 \[cfg2.\]%
+        %  new libbuild2-foo/1.0.0 \[cfg2.\]%
+          new libbiz/1.0.0
+        %continue\? \[Y/n\] fetched libbaz/1.0.0 \[cfg3.\]%
+        %unpacked libbaz/1.0.0 \[cfg3.\]%
+        %fetched foo/1.0.0 \[cfg3.\]%
+        %unpacked foo/1.0.0 \[cfg3.\]%
+        %fetched libbuild2-bar/1.0.0 \[cfg2.\]%
+        %unpacked libbuild2-bar/1.0.0 \[cfg2.\]%
+        %fetched libbaz/1.0.0 \[cfg2.\]%
+        %unpacked libbaz/1.0.0 \[cfg2.\]%
+        %fetched libbuild2-foo/1.0.0 \[cfg2.\]%
+        %unpacked libbuild2-foo/1.0.0 \[cfg2.\]%
+        fetched libbiz/1.0.0
+        unpacked libbiz/1.0.0
+        %configured libbaz/1.0.0 \[cfg3.\]%
+        %configured foo/1.0.0 \[cfg3.\]%
+        %configured libbuild2-bar/1.0.0 \[cfg2.\]%
+        %configured libbaz/1.0.0 \[cfg2.\]%
+        %configured libbuild2-foo/1.0.0 \[cfg2.\]%
+        configured libbiz/1.0.0
+        %info: cfg2.+libbaz-1.0.0.+ is up to date%
+        %info: cfg2.+libbuild2-foo-1.0.0.+ is up to date%
+        %info: cfg.+libbiz-1.0.0.+ is up to date%
+        %updated libbaz/1.0.0 \[cfg2.\]%
+        %updated libbuild2-foo/1.0.0 \[cfg2.\]%
+        updated libbiz/1.0.0
+        EOE
+
+      $pkg_status -d cfg -r >>/EOO;
+        !libbiz configured 1.0.0
+          foo [cfg3/] configured 1.0.0
+            libbaz [cfg3/] configured 1.0.0
+          libbaz [cfg2/] configured 1.0.0
+          libbuild2-foo [cfg2/] configured 1.0.0
+            foo [cfg3/] configured 1.0.0
+              libbaz [cfg3/] configured 1.0.0
+            libbaz [cfg2/] configured 1.0.0
+            libbuild2-bar [cfg2/] configured 1.0.0
+        EOO
+
+      $pkg_drop libbiz
+    }
+
+    : duplicates
+    :
+    {
+      $cfg_create -d cfg &cfg/***;
+      $rep_add $rep/t7a && $rep_fetch;
+
+      $cfg_create -d cfg2 --name cfg2 &cfg2/***;
+      $cfg_link -d cfg cfg2;
+
+      $cfg_create -d cfg3 --name cfg3 &cfg3/***;
+      $cfg_link -d cfg cfg3;
+
+      $* libbiz +{ --config-name cfg2 } --yes 2>!;
+      $* libbuz +{ --config-name cfg3 } --yes 2>!;
+
+      $* libbix 2>>/~%EOE% != 0
+        error: building build system module libbuild2-bar in multiple configurations
+        %  info: cfg(2|3)/.bpkg/build2/%{2}
+        EOE
+    }
+  }
+}
diff --git a/tests/pkg-build/t7a b/tests/pkg-build/t7a
new file mode 120000
index 0000000..d02b5d4
--- /dev/null
+++ b/tests/pkg-build/t7a
@@ -0,0 +1 @@
+../common/linked/t7a
\ No newline at end of file
diff --git a/tests/pkg-build/t7b b/tests/pkg-build/t7b
new file mode 120000
index 0000000..808039d
--- /dev/null
+++ b/tests/pkg-build/t7b
@@ -0,0 +1 @@
+../common/linked/t7b
\ No newline at end of file
diff --git a/tests/pkg-drop.testscript b/tests/pkg-drop.testscript
index db9cf7c..eb3d8ff 100644
--- a/tests/pkg-drop.testscript
+++ b/tests/pkg-drop.testscript
@@ -9,16 +9,31 @@
 # |-- t4a
 # |   |-- libfoo-1.1.0.tar.gz
 # |   `-- repositories.manifest
+# |
 # |-- t4b                     -> t4a (prerequisite repository)
 # |   |-- libbar-1.1.0.tar.gz -> libfoo == 1.1.0
 # |   `-- repositories.manifest
+# |
 # |-- t4c                     -> t4b (prerequisite repository)
 # |   |-- libbaz-1.1.0.tar.gz -> libfoo, libbar
 # |   |-- libfoo-1.0.0.tar.gz
 # |   `-- repositories.manifest
-# `-- t4d                     -> t4c (complement)
-#     |-- libbiz-1.0.0.tar.gz -> libfox, libfoo, libbaz
-#     |-- libfox-1.0.0.tar.gz
+# |
+# |-- t4d                     -> t4c (complement)
+# |   |-- libbiz-1.0.0.tar.gz -> libfox, libfoo, libbaz
+# |   |-- libfox-1.0.0.tar.gz
+# |   `-- repositories.manifest
+# |
+# |-- t7a
+# |   |-- libbaz-1.0.0.tar.gz
+# |   |-- foo-1.0.0.tar.gz      -> libbaz ^1.0.0
+# |   |-- libbar-1.0.0.tar.gz   -> * foo ^1.0.0, libbaz ^1.0.0
+# |   `-- repositories.manifest
+# |
+# `-- t7b                       -> t7a (complement repository)
+#     |-- libbaz-1.1.0.tar.gz
+#     |-- foo-1.1.0.tar.gz      -> libbaz ^1.1.0
+#     |-- libbar-1.1.0.tar.gz   -> * foo ^1.1.0, libbaz ^1.0.0
 #     `-- repositories.manifest
 
 # Prepare repositories used by tests if running in the local mode.
@@ -30,8 +45,12 @@
   cp -r $src/t4b $out/t4b && $rep_create $out/t4b &$out/t4b/packages.manifest
   cp -r $src/t4c $out/t4c && $rep_create $out/t4c &$out/t4c/packages.manifest
   cp -r $src/t4d $out/t4d && $rep_create $out/t4d &$out/t4d/packages.manifest
+  cp -r $src/t7a $out/t7a && $rep_create $out/t7a &$out/t7a/packages.manifest
+  cp -r $src/t7b $out/t7b && $rep_create $out/t7b &$out/t7b/packages.manifest
 end
 
+cfg_create += 2>!
+cfg_link   += 2>!
 pkg_build  += -d cfg --yes 2>!
 pkg_status += -d cfg
 rep_add    += -d cfg 2>!
@@ -444,3 +463,269 @@ $* libfoo/1.0.0 2>>~%EOE% != 0
 
   $* libfoo 2>'purged libfoo'
 }
+
+: linked-configs
+:
+{
+  : 3-configs
+  :
+  {
+    +$clone_root_cfg && $rep_add $rep/t4c && $rep_fetch
+
+    +$cfg_create -d cfg-bar &cfg-bar/***
+    +$cfg_create -d cfg-foo &cfg-foo/***
+
+    +$cfg_link -d cfg     cfg-bar
+    +$cfg_link -d cfg-bar cfg-foo
+
+    : baz
+    :
+    {
+      $clone_cfg;
+      cp -pr ../cfg-bar ./;
+      cp -pr ../cfg-foo ./;
+
+      $pkg_build libbar@"$rep/t4b" -d cfg-bar ?libfoo +{ --config-id 2 } --trust-yes 2>!;
+      $pkg_build libbaz 2>!;
+
+      $pkg_build '?libbar' +{ --config-id 1 } 2>!;
+
+      $* libbaz <<EOI 2>>/~%EOE%
+          y
+          y
+          EOI
+          following dependencies were automatically built but will no longer be used:
+            libbar [cfg-bar/]
+            libfoo [cfg-foo/]
+          %drop unused packages\? \[Y.n\]   drop libbaz%
+            drop libbar [cfg-bar/]
+            drop libfoo [cfg-foo/]
+          %continue\? \[Y.n\] disfigured libbaz%
+          disfigured libbar [cfg-bar/]
+          disfigured libfoo [cfg-foo/]
+          purged libbaz
+          purged libbar [cfg-bar/]
+          purged libfoo [cfg-foo/]
+          EOE
+    }
+
+    : foo
+    :
+    {
+      $clone_cfg;
+      cp -pr ../cfg-bar ./;
+      cp -pr ../cfg-foo ./;
+
+      $pkg_build libbar@"$rep/t4b" -d cfg-bar ?libfoo +{ --config-id 2 } --trust-yes 2>!;
+      $pkg_build libbaz 2>!;
+
+      # Make sure that dependents of a package being dropped can be found in
+      # implicitly linked configurations recursively. Note that configuring
+      # libbar as system, we make libbaz an only dependent of libfoo.
+      #
+      $pkg_build '?sys:libbar' +{ --config-id 1 } 2>!;
+
+      $pkg_status -r libbaz >>/EOO;
+        !libbaz configured 1.1.0
+          libbar [cfg-bar/] configured,system !* available [1.1.0]
+          libfoo [cfg-foo/] configured 1.1.0
+        EOO
+
+        $pkg_status -d cfg-bar -r libbar >>EOO;
+          libbar configured,system !* available 1.1.0
+          EOO
+
+        $pkg_status -d cfg-foo libfoo >'libfoo configured 1.1.0';
+
+        $* -d cfg-foo libfoo <<EOI 2>>/~%EOE%;
+          y
+          y
+          y
+          EOI
+          following dependent packages will have to be dropped as well:
+            libbaz [cfg/] (requires libfoo)
+          %drop dependent packages\? \[y.N\] following dependencies were automatically built but will no longer be used:%
+            sys:libbar [cfg-bar/]
+          %drop unused packages\? \[Y.n\]   drop libbaz \[cfg/\]%
+            drop libfoo
+            drop libbar [cfg-bar/]
+          %continue\? \[Y.n\] disfigured libbaz \[cfg/\]%
+          disfigured libfoo
+          purged libbar [cfg-bar/]
+          purged libbaz [cfg/]
+          purged libfoo
+          EOE
+
+      $pkg_status            libbaz >'libbaz available 1.1.0';
+      $pkg_status -d cfg-bar libbar >'libbar available 1.1.0';
+      $pkg_status -d cfg-foo libfoo >'libfoo unknown'
+    }
+
+    : bar
+    :
+    {
+      $clone_cfg;
+      cp -pr ../cfg-bar ./;
+      cp -pr ../cfg-foo ./;
+
+      # Test that if we turn implicit links into explicit, then all dependents
+      # are still discovered.
+      #
+      $cfg_link -d cfg-bar cfg;
+      $cfg_link -d cfg-foo cfg-bar;
+
+      $pkg_build libbar@"$rep/t4b" -d cfg-bar ?libfoo +{ --config-id 2 } --trust-yes 2>!;
+      $pkg_build libbaz 2>!;
+
+      $pkg_status -r libbaz >>/EOO;
+        !libbaz configured 1.1.0
+          !libbar [cfg-bar/] configured !1.1.0
+            libfoo [cfg-foo/] configured 1.1.0
+          libfoo [cfg-foo/] configured 1.1.0
+        EOO
+
+      $pkg_status -d cfg-bar -r libbar >>/EOO;
+        !libbar configured !1.1.0
+          libfoo [cfg-foo/] configured 1.1.0
+        EOO
+
+      $pkg_status -d cfg-foo libfoo >'libfoo configured 1.1.0';
+
+      $* -d cfg-bar libbar <<EOI 2>>/~%EOE%;
+        y
+        y
+        y
+        EOI
+        following dependent packages will have to be dropped as well:
+          libbaz [cfg/] (requires libbar)
+        %drop dependent packages\? \[y.N\] following dependencies were automatically built but will no longer be used:%
+          libfoo [cfg-foo/]
+        %drop unused packages\? \[Y.n\]   drop libbaz \[cfg/\]%
+          drop libbar
+          drop libfoo [cfg-foo/]
+        %continue\? \[Y.n\] disfigured libbaz \[cfg/\]%
+        disfigured libbar
+        disfigured libfoo [cfg-foo/]
+        purged libbaz [cfg/]
+        purged libbar
+        purged libfoo [cfg-foo/]
+        EOE
+
+      $pkg_status            libbaz >'libbaz available 1.1.0';
+      $pkg_status -d cfg-bar libbar >'libbar available 1.1.0';
+      $pkg_status -d cfg-foo libfoo >'libfoo unknown'
+    }
+  }
+}
+
+: buildtime-dep
+:
+{
+  +$clone_cfg && $rep_add $rep/t7a && $rep_fetch
+  +$cfg_create -d cfg2 --type host &cfg2/***
+  +$cfg_link -d cfg cfg2
+
+  : drop-dependent
+  :
+  {
+    $clone_cfg;
+    cp -pr ../cfg2 ./;
+
+    $pkg_build libbar --yes >!;
+
+    $* libbar <<EOI 2>>/~%EOE%;
+      y
+      y
+      EOI
+      following dependencies were automatically built but will no longer be used:
+        foo [cfg2/]
+        libbaz [cfg2/]
+        libbaz
+      %drop unused packages\? \[Y.n\]   drop libbar%
+        drop foo [cfg2/]
+        drop libbaz [cfg2/]
+        drop libbaz
+      %continue\? \[Y.n\] disfigured libbar%
+      disfigured foo [cfg2/]
+      disfigured libbaz [cfg2/]
+      disfigured libbaz
+      purged libbar
+      purged foo [cfg2/]
+      purged libbaz [cfg2/]
+      purged libbaz
+      EOE
+
+    $pkg_status -r libbar >'libbar available 1.0.0'
+  }
+
+  : drop-dependency
+  :
+  {
+    $clone_cfg;
+    cp -pr ../cfg2 ./;
+
+    $pkg_build libbar --yes >!;
+
+    $* -d cfg2 libbaz <<EOI 2>>/~%EOE%;
+      y
+      y
+      y
+      EOI
+      following dependent packages will have to be dropped as well:
+        foo (requires libbaz)
+        libbar [cfg/] (requires foo)
+      %drop dependent packages\? \[y.N\] following dependencies were automatically built but will no longer be used:%
+        libbaz [cfg/]
+      %drop unused packages\? \[Y.n\]   drop libbar \[cfg.\]%
+        drop foo
+        drop libbaz
+        drop libbaz [cfg/]
+      %continue\? \[Y.n\] disfigured libbar \[cfg.\]%
+      disfigured foo
+      disfigured libbaz
+      disfigured libbaz [cfg/]
+      purged libbar [cfg/]
+      purged foo
+      purged libbaz
+      purged libbaz [cfg/]
+      EOE
+
+    $pkg_status -r libbar >'libbar available 1.0.0'
+  }
+
+  : skip-deleted-dependency
+  :
+  {
+    $clone_cfg;
+    cp -pr ../cfg2 ./;
+
+    $pkg_build libbar --yes >! &cfg/lib*/*** &cfg/lib*;
+
+    mv cfg cfg.tmp;
+
+    $* -d cfg2 libbaz <<EOI 2>>/~%EOE%;
+      y
+      y
+      EOI
+      following dependent packages will have to be dropped as well:
+        foo (requires libbaz)
+      %drop dependent packages\? \[y.N\]   drop foo%
+        drop libbaz
+      %continue\? \[Y.n\] disfigured foo%
+      disfigured libbaz
+      purged foo
+      purged libbaz
+      EOE
+
+    # While at it, test that we properly handle the missing prerequisite
+    # situation.
+    #
+    mv cfg.tmp cfg;
+
+    $* libbar 2>>/EOE != 0;
+      error: unable to find prerequisite package foo in linked configuration cfg2/
+      EOE
+
+    $pkg_status -d cfg2 -r 2>'info: no held packages in the configuration'
+  }
+}
diff --git a/tests/pkg-drop/t7a b/tests/pkg-drop/t7a
new file mode 120000
index 0000000..d02b5d4
--- /dev/null
+++ b/tests/pkg-drop/t7a
@@ -0,0 +1 @@
+../common/linked/t7a
\ No newline at end of file
diff --git a/tests/pkg-drop/t7b b/tests/pkg-drop/t7b
new file mode 120000
index 0000000..808039d
--- /dev/null
+++ b/tests/pkg-drop/t7b
@@ -0,0 +1 @@
+../common/linked/t7b
\ No newline at end of file