Ensure backtrack loop termination.
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 3ed81e4..054dc8c 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -5531,11 +5531,15 @@
 
 		if success or mydepgraph.success_without_autounmask():
 			break
+		elif not allow_backtracking:
+			break
 		elif backtracked > max_retries:
 			break
 		elif mydepgraph.need_restart():
 			backtracked += 1
-			backtracker.feedback(mydepgraph.get_backtrack_infos())	
+			backtracker.feedback(mydepgraph.get_backtrack_infos())
+		else:
+			break
 
 	if not (success or mydepgraph.success_without_autounmask()) and backtracked: