py3: use raw string for file open mode
Otherwise the module importer rewrites it to bytes on Python 3,
which angers Python 3.
Differential Revision: https://phab.mercurial-scm.org/D2137
--- a/mercurial/archival.py Sun Feb 11 10:49:00 2018 -0800
+++ b/mercurial/archival.py Sun Feb 11 10:52:13 2018 -0800
@@ -218,7 +218,7 @@
dest.tell()
except (AttributeError, IOError):
dest = tellable(dest)
- self.z = zipfile.ZipFile(dest, 'w',
+ self.z = zipfile.ZipFile(dest, r'w',
compress and zipfile.ZIP_DEFLATED or
zipfile.ZIP_STORED)