unit_store.go.diff

diff --git a/store/unit_store.go b/store/unit_store.go
index 515ed9c..e145bd0 100644
--- a/store/unit_store.go
+++ b/store/unit_store.go
@@ -90,10 +90,8 @@ func (s unitStores) Refs(f ...RefFilter) ([]*graph.Ref, error) {
 	}
 
 	c_unitStores_Refs_last_numUnitsQueried = 0
-	var (
-		allRefs   []*graph.Ref
-		allRefsMu sync.Mutex
-	)
+
+	allRefsChan := make(chan *graph.Ref)
 	par := parallel.NewRun(storeFetchPar)
 	for u, us := range uss {
 		if us == nil {
@@ -139,16 +137,24 @@ func (s unitStores) Refs(f ...RefFilter) ([]*graph.Ref, error) {
 				if ref.DefUnit == "" {
 					ref.DefUnit = u.Name
 				}
+				allRefsChan <- ref
 			}
 
-			allRefsMu.Lock()
-			allRefs = append(allRefs, refs...)
-			allRefsMu.Unlock()
 			return nil
 		})
 	}
-	err = par.Wait()
-	return allRefs, err
+	var parErr error
+	go func() {
+		parErr = par.Wait()
+		close(allRefsChan)
+	}()
+
+	var allRefs []*graph.Ref
+	for ref := range allRefsChan {
+		allRefs = append(allRefs, ref)
+	}
+
+	return allRefs, parErr
 }
 
 func cleanForImport(data *graph.Output, repo, unitType, unit string) {