fix test_unsupported_hashes for windows

Author: xavfernandez

tests/unit/test_req.py

@@ -161,6 +161,9 @@ def test_unsupported_hashes(self, data):
                 'file',
                 2))[0])
         finder = PackageFinder([data.find_links], [], session=PipSession())
+        sep = os.path.sep
+        if sep == '\\':
+            sep = '\\\\'  # This needs to be escaped for the regex
         assert_raises_regexp(
             HashErrors,
             r"Can't verify hashes for these requirements because we don't "
@@ -169,7 +172,8 @@ def test_unsupported_hashes(self, data):
             r"\(line 1\)\)\n"
             r"Can't verify hashes for these file:// requirements because they "
             r"point to directories:\n"
-            r"    file:///.*/data/packages/FSPkg \(from -r file \(line 2\)\)",
+            r"    file://.*{sep}data{sep}packages{sep}FSPkg "
+            "\(from -r file \(line 2\)\)".format(sep=sep),
             reqset.prepare_files,
             finder)