diff -r 31a2eb0f74e5 -r d5b2beca16c0 mercurial/vfs.py
--- a/mercurial/vfs.py	Wed Aug 30 14:04:55 2017 -0700
+++ b/mercurial/vfs.py	Tue Aug 22 20:03:07 2017 -0400
@@ -16,6 +16,7 @@
 
 from .i18n import _
 from . import (
+    encoding,
     error,
     pathutil,
     pycompat,
@@ -434,7 +435,8 @@
                 os.symlink(src, linkname)
             except OSError as err:
                 raise OSError(err.errno, _('could not symlink to %r: %s') %
-                              (src, err.strerror), linkname)
+                              (src, encoding.strtolocal(err.strerror)),
+                              linkname)
         else:
             self.write(dst, src)