Expect failure running Python 3 only tests on Python 2

setuptools/tests/__init__.py

@@ -20,6 +20,7 @@ c_type = os.environ.get("LC_CTYPE", os.environ.get("LC_ALL"))
 is_ascii = c_type in ("C", "POSIX")
 fail_on_ascii = pytest.mark.xfail(is_ascii, reason="Test fails in this locale")
 
+
 def makeSetup(**args):
     """Return distribution from 'setup(**args)', without executing commands"""
 

setuptools/tests/test_sdist.py

@@ -8,6 +8,8 @@ import tempfile
 import unicodedata
 import contextlib
 
+import pytest
+
 import pkg_resources
 from setuptools.compat import StringIO, unicode, PY3, PY2
 from setuptools.command.sdist import sdist
@@ -16,6 +18,9 @@ from setuptools.dist import Distribution
 from setuptools.tests import fail_on_ascii
 
 
+py3_only = pytest.mark.xfail(PY2, reason="Test runs on Python 3 only")
+
+
 SETUP_ATTRS = {
     'name': 'sdist_test',
     'version': '0.0',
@@ -181,9 +186,7 @@ class TestSdistTest:
 
         assert posix(filename) in u_contents
 
-    # Python 3 only
-    if PY3:
-
+    @py3_only
     def test_write_manifest_allows_utf8_filenames(self):
         # Test for #303.
         dist = Distribution(SETUP_ATTRS)
@@ -219,6 +222,7 @@ class TestSdistTest:
         # The filelist should have been updated as well
         assert u_filename in mm.filelist.files
 
+    @py3_only
     def test_write_manifest_skips_non_utf8_filenames(self):
         """
         Files that cannot be encoded to UTF-8 (specifically, those that
@@ -288,9 +292,7 @@ class TestSdistTest:
             filename = filename.decode('utf-8')
         assert filename in cmd.filelist.files
 
-    # Python 3 only
-    if PY3:
-
+    @py3_only
     def test_read_manifest_skips_non_utf8_filenames(self):
         # Test for #303.
         dist = Distribution(SETUP_ATTRS)