buildenv: paths to link resolving to the same absolute path is not a conflict

When building an environment if two paths conflict but one or both are
symbolic links and they resolve to the same real path, the conflict is
discarded because the contents of both paths are the same. One of them
is chosen and there is no need to recur into them in order to build
deeper symbolic links.

1 files changed, 9 insertions, 0 deletions

diff --git a/pkgs/build-support/buildenv/builder.pl b/pkgs/build-support/buildenv/builder.pl
index fc6ffce735c..411b147cc58 100755
--- a/pkgs/build-support/buildenv/builder.pl
+++ b/pkgs/build-support/buildenv/builder.pl
@@ -129,6 +129,15 @@ sub findFiles {
         return;
     }
 
+    # If target already exists and both targets resolves to the same path, skip
+    if (defined $oldTarget && $oldTarget ne "" && abs_path($target) eq abs_path($oldTarget)) {
+        # Prefer the target that is not a symlink, if any
+        if (-l $oldTarget && ! -l $target) {
+            $symlinks{$relName} = [$target, $priority];
+        }
+        return;
+    }
+
     # If target already exists as a symlink to a file (not a
     # directory) in a higher-priority package, skip.
     if (defined $oldTarget && $priority > $oldPriority && $oldTarget ne "" && ! -d $oldTarget) {