--- a/mercurial/repair.py	Sun Mar 26 16:33:12 2017 +0900
+++ b/mercurial/repair.py	Sun Mar 26 16:53:28 2017 -0700
@@ -163,8 +163,7 @@
     curtr = repo.currenttransaction()
     if curtr is not None:
         del curtr  # avoid carrying reference to transaction for nothing
-        msg = _('programming error: cannot strip from inside a transaction')
-        raise error.Abort(msg, hint=_('contact your extension maintainer'))
+        raise error.ProgrammingError('cannot strip from inside a transaction')
 
     try:
         with repo.transaction("strip") as tr: