python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/test/test_wait4.py

@@ -0,0 +1,39 @@
+"""This test checks for correct wait4() behavior.
+"""
+
+import os
+import time
+import sys
+import unittest
+from test.fork_wait import ForkWait
+from test.support import reap_children, get_attribute
+
+# If either of these do not exist, skip this test.
+get_attribute(os, 'fork')
+get_attribute(os, 'wait4')
+
+
+class Wait4Test(ForkWait):
+    def wait_impl(self, cpid):
+        option = os.WNOHANG
+        if sys.platform.startswith('aix'):
+            # Issue #11185: wait4 is broken on AIX and will always return 0
+            # with WNOHANG.
+            option = 0
+        deadline = time.monotonic() + 10.0
+        while time.monotonic() <= deadline:
+            # wait4() 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.wait4(cpid, option)
+            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()