diff -r aac4be30e250 -r 2ce60954b1b7 mercurial/pycompat.py
--- a/mercurial/pycompat.py	Sat May 26 12:14:04 2018 +0900
+++ b/mercurial/pycompat.py	Sat May 26 12:20:36 2018 +0900
@@ -386,6 +386,9 @@
 def gnugetoptb(args, shortlist, namelist):
     return _getoptbwrapper(getopt.gnu_getopt, args, shortlist, namelist)
 
+def mkdtemp(suffix=b'', prefix=b'tmp', dir=None):
+    return tempfile.mkdtemp(suffix, prefix, dir)
+
 # text=True is not supported; use util.from/tonativeeol() instead
 def mkstemp(suffix=b'', prefix=b'tmp', dir=None):
     return tempfile.mkstemp(suffix, prefix, dir)