diff -r ca443bac7ed4 -r 2c097e22492c mercurial/hg.py
--- a/mercurial/hg.py	Thu May 28 17:03:35 2009 +0200
+++ b/mercurial/hg.py	Thu May 28 17:44:57 2009 +0200
@@ -165,7 +165,7 @@
                 # can end up with extra data in the cloned revlogs that's
                 # not pointed to by changesets, thus causing verify to
                 # fail
-                src_lock = src_repo.lock()
+                src_lock = src_repo.lock(wait=False)
             except error.LockError:
                 copy = False