diff -r 13f7a6a4f0db -r a5493a251ad3 mercurial/thirdparty/attr/_make.py
--- a/mercurial/thirdparty/attr/_make.py	Sun Jan 27 13:37:37 2019 +0900
+++ b/mercurial/thirdparty/attr/_make.py	Mon Feb 04 09:10:07 2019 -0800
@@ -56,7 +56,7 @@
 def attr(default=NOTHING, validator=None,
          repr=True, cmp=True, hash=None, init=True,
          convert=None, metadata={}):
-    """
+    r"""
     Create a new attribute on a class.
 
     ..  warning::