--- a/mercurial/windows.py	Wed Jan 16 16:49:15 2019 -0800
+++ b/mercurial/windows.py	Thu Jan 10 14:57:01 2019 +0100
@@ -248,7 +248,7 @@
 def setflags(f, l, x):
     pass
 
-def copymode(src, dst, mode=None):
+def copymode(src, dst, mode=None, enforcewritable=False):
     pass
 
 def checkexec(path):