diff -r 6097a616178d -r 1632999d4bed mercurial/changegroup.py
--- a/mercurial/changegroup.py	Sun Sep 10 18:47:39 2017 -0700
+++ b/mercurial/changegroup.py	Sun Sep 10 18:48:42 2017 -0700
@@ -21,7 +21,6 @@
 
 from . import (
     dagutil,
-    discovery,
     error,
     mdiff,
     phases,
@@ -951,12 +950,6 @@
     return makechangegroup(repo, outgoing, version, source,
                            bundlecaps=bundlecaps)
 
-def changegroup(repo, basenodes, source):
-    # to avoid a race we use changegroupsubset() (issue1320)
-    outgoing = discovery.outgoing(repo, missingroots=basenodes,
-                                  missingheads=repo.heads())
-    return makechangegroup(repo, outgoing, '01', source)
-
 def _addchangegroupfiles(repo, source, revmap, trp, expectedfiles, needfiles):
     revisions = 0
     files = 0