Remove sys.modules hack

Fix #1888 (metadata accidentally not picklable), and removes a case where reimporting a vendored module results in a second copy of the same module.

1 files changed, 22 insertions, 0 deletions

diff --git a/setuptools/tests/test_extern.py b/setuptools/tests/test_extern.py
new file mode 100644
index 00000000..3519a680
--- /dev/null
+++ b/setuptools/tests/test_extern.py
@@ -0,0 +1,22 @@
+import importlib
+import pickle
+
+from setuptools import Distribution
+from setuptools.extern import ordered_set
+from setuptools.tests import py3_only
+
+
+def test_reimport_extern():
+    ordered_set2 = importlib.import_module(ordered_set.__name__)
+    assert ordered_set is ordered_set2
+
+
+def test_orderedset_pickle_roundtrip():
+    o1 = ordered_set.OrderedSet([1, 2, 5])
+    o2 = pickle.loads(pickle.dumps(o1))
+    assert o1 == o2
+
+
+@py3_only
+def test_distribution_picklable():
+    pickle.loads(pickle.dumps(Distribution()))