Issue 10556: test_zipimport_support implicitly imports too many modules (including _ssl) to safely clobber sys.modules after each test
diff --git a/Lib/test/support.py b/Lib/test/support.py
index 152cac9..3d1d0f1 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -1199,6 +1199,12 @@
if k.startswith('encodings.')]
sys.modules.clear()
sys.modules.update(encodings)
+ # XXX: This kind of problem can affect more than just encodings. In particular
+ # extension modules (such as _ssl) don't cope with releoding properly.
+ # Really, test modules should be cleaning out the test specific modules they
+ # know they added (ala test_runpy) rather than relying on this function (as
+ # test_importhooks and test_pkg do currently).
+ # Implicitly imported *real* modules should be left alone (see issue 10556).
sys.modules.update(oldmodules)
#=======================================================================