--- a/tests/test-propertycache.py	Wed Oct 17 21:00:36 2018 +0800
+++ b/tests/test-propertycache.py	Thu Sep 27 21:54:13 2018 -0400
@@ -16,6 +16,10 @@
     util,
 )
 
+from mercurial.utils import (
+    procutil,
+)
+
 # create some special property cache that trace they call
 
 calllog = []
@@ -46,7 +50,9 @@
 # Create an empty repo and instantiate it. It is important to run
 # these tests on the real object to detect regression.
 repopath = pycompat.fsencode(os.path.join(os.environ['TESTTMP'], 'repo'))
-assert subprocess.call(['hg', 'init', repopath]) == 0
+assert subprocess.call(pycompat.rapply(procutil.tonativestr,
+                                       [b'hg', b'init', repopath])) == 0
+
 ui = uimod.ui.load()
 repo = hg.repository(ui, path=repopath).unfiltered()