Tighten/optimize cleaning of fsdir{} during match

1 files changed, 10 insertions, 1 deletions

diff --git a/libbuild2/algorithm.cxx b/libbuild2/algorithm.cxx
index 4ec4db5..1f2d88b 100644
--- a/libbuild2/algorithm.cxx
+++ b/libbuild2/algorithm.cxx
@@ -3137,7 +3137,14 @@ namespace build2
     // Let's keep this as close to update_during_match() semantically as
     // possible until we see a clear reason to deviate.
 
-    assert (a == perform_clean_id);
+    // We have a problem with fsdir{}: if the directory is not empty because
+    // there are other targets that depend on it and we execute it here and
+    // now, it will not remove the directory (because it's not yet empty) but
+    // will cause the target to be in the executed state, which means that
+    // when other targets try to execute it, it will be a noop and the
+    // directory will be left behind.
+
+    assert (a == perform_clean_id && !t.is_a<fsdir> ());
 
     target_state os (t.matched_state (a));
 
@@ -3194,6 +3201,8 @@ namespace build2
         {
           const target& pt (*p.target);
 
+          assert (!pt.is_a<fsdir> ()); // See above.
+
           target_state os (pt.matched_state (a));
 
           if (os != target_state::unchanged)