use markerlib

--HG--
branch : distribute
extra : rebase_source : a684fafb1aeb44954bdb8604a77fcc8d1549648c

pkg_resources.py

@@ -2474,7 +2474,7 @@ class DistInfoDistribution(Distribution):
                 return True
             return marker_fn
         try:
-            from wheel.markers import as_function
+            from markerlib import as_function
         except ImportError:
             as_function = dummy_marker
         dm = self.__dep_map = {None: []}