--- a/hgext/strip.py	Mon Jun 17 10:19:41 2019 -0700
+++ b/hgext/strip.py	Mon Jun 17 10:53:00 2019 -0700
@@ -31,21 +31,6 @@
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
-def checksubstate(repo, baserev=None):
-    '''return list of subrepos at a different revision than substate.
-    Abort if any subrepos have uncommitted changes.'''
-    inclsubs = []
-    wctx = repo[None]
-    if baserev:
-        bctx = repo[baserev]
-    else:
-        bctx = wctx.p1()
-    for s in sorted(wctx.substate):
-        wctx.sub(s).bailifchanged(True)
-        if s not in bctx.substate or bctx.sub(s).dirty():
-            inclsubs.append(s)
-    return inclsubs
-
 def checklocalchanges(repo, force=False):
     cmdutil.checkunfinished(repo)
     s = repo.status()