diff -r d51c658d3f04 -r 56b2bcea2529 mercurial/treediscovery.py
--- a/mercurial/treediscovery.py	Mon Oct 05 22:49:24 2015 -0700
+++ b/mercurial/treediscovery.py	Thu Oct 08 12:55:45 2015 -0700
@@ -16,7 +16,6 @@
 )
 from . import (
     error,
-    util,
 )
 
 def findcommonincoming(repo, remote, heads=None, force=False):
@@ -149,7 +148,7 @@
         if force:
             repo.ui.warn(_("warning: repository is unrelated\n"))
         else:
-            raise util.Abort(_("repository is unrelated"))
+            raise error.Abort(_("repository is unrelated"))
 
     repo.ui.debug("found new changesets starting at " +
                  " ".join([short(f) for f in fetch]) + "\n")