diff -r 6b77c13a1aab -r e1458bce84db tests/hghave.py
--- a/tests/hghave.py	Wed Oct 18 18:29:00 2017 -0400
+++ b/tests/hghave.py	Wed Oct 18 18:29:17 2017 -0400
@@ -442,7 +442,7 @@
 @check("clang-format", "clang-format C code formatter")
 def has_clang_format():
     return matchoutput("clang-format --help",
-                       r"^OVERVIEW: A tool to format C/C\+\+[^ ]+ code.")
+                       br"^OVERVIEW: A tool to format C/C\+\+[^ ]+ code.")
 
 @check("pygments", "Pygments source highlighting library")
 def has_pygments():