--- a/mercurial/pycompat.py	Mon Nov 05 17:48:23 2018 -0500
+++ b/mercurial/pycompat.py	Mon Nov 05 19:52:42 2018 -0800
@@ -403,7 +403,8 @@
 
 isjython = sysplatform.startswith(b'java')
 
-isdarwin = sysplatform == b'darwin'
+isdarwin = sysplatform.startswith(b'darwin')
+islinux = sysplatform.startswith(b'linux')
 isposix = osname == b'posix'
 iswindows = osname == b'nt'