diff -r 238abf65a8ad -r dacfcdd8b94e mercurial/util.py
--- a/mercurial/util.py	Thu Oct 12 09:04:22 2017 -0700
+++ b/mercurial/util.py	Thu Oct 12 23:34:34 2017 -0700
@@ -1561,7 +1561,7 @@
 
 def gui():
     '''Are we running in a GUI?'''
-    if pycompat.sysplatform == 'darwin':
+    if pycompat.isdarwin:
         if 'SSH_CONNECTION' in encoding.environ:
             # handle SSH access to a box where the user is logged in
             return False