Merge pull request #6469 from gbpdt/fix/skipped_build_locking

Unlock output paths when a derivation is already built

(cherry picked from commit 7ba4e073e8622ca86b52e03d68476e80250ab62f)
Change-Id: I9de077679290d5141a610ac43d99d3a43acff87c

src/libstore/build/derivation-goal.cc

@@ -1474,6 +1474,7 @@ void DerivationGoal::done(
     SingleDrvOutputs builtOutputs,
     std::optional<Error> ex)
 {
+    outputLocks.unlock();
     buildResult.status = status;
     if (ex)
         buildResult.errorMsg = fmt("%s", normaltxt(ex->info().msg));