python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/test/test_wait3.py

@@ -0,0 +1,38 @@
+"""This test checks for correct wait3() behavior.
+"""
+
+import os
+import time
+import unittest
+from test.fork_wait import ForkWait
+from test.support import reap_children
+
+if not hasattr(os, 'fork'):
+    raise unittest.SkipTest("os.fork not defined")
+
+if not hasattr(os, 'wait3'):
+    raise unittest.SkipTest("os.wait3 not defined")
+
+class Wait3Test(ForkWait):
+    def wait_impl(self, cpid):
+        # This many iterations can be required, since some previously run
+        # tests (e.g. test_ctypes) could have spawned a lot of children
+        # very quickly.
+        deadline = time.monotonic() + 10.0
+        while time.monotonic() <= deadline:
+            # wait3() shouldn't hang, but some of the buildbots seem to hang
+            # in the forking tests.  This is an attempt to fix the problem.
+            spid, status, rusage = os.wait3(os.WNOHANG)
+            if spid == cpid:
+                break
+            time.sleep(0.1)
+
+        self.assertEqual(spid, cpid)
+        self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
+        self.assertTrue(rusage)
+
+def tearDownModule():
+    reap_children()
+
+if __name__ == "__main__":
+    unittest.main()