diff -r b39958d6b81b -r aac4be30e250 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Thu May 03 18:39:58 2018 +0900
+++ b/mercurial/debugcommands.py	Sat May 26 12:14:04 2018 +0900
@@ -1142,7 +1142,7 @@
     opts = pycompat.byteskwargs(opts)
 
     def writetemp(contents):
-        (fd, name) = tempfile.mkstemp(prefix="hg-debuginstall-")
+        (fd, name) = pycompat.mkstemp(prefix="hg-debuginstall-")
         f = os.fdopen(fd, r"wb")
         f.write(contents)
         f.close()