diff -r d60678a567a9 -r 328739ea70c3 mercurial/config.py
--- a/mercurial/config.py	Tue Jun 23 22:38:21 2015 -0700
+++ b/mercurial/config.py	Tue Jun 23 22:20:08 2015 -0700
@@ -122,7 +122,7 @@
                     try:
                         include(inc, remap=remap, sections=sections)
                         break
-                    except IOError, inst:
+                    except IOError as inst:
                         if inst.errno != errno.ENOENT:
                             raise error.ParseError(_("cannot include %s (%s)")
                                                    % (inc, inst.strerror),