More tweaks for 3.7

src/gevent/tests/test__fileobject.py

@@ -183,6 +183,23 @@ class TestFileObjectThread(ConcurrentFileObjectMixin,
     def _getTargetClass(self):
         return fileobject.FileObjectThread
 
+    def tearDown(self):
+        # Make sure outstanding tasks have completed.
+        # On Travis with Python 3.7 and libuv, test_bufsize_0
+        # fails in os.fdopen(), claiming the file descriptor is bad.
+        # This would happen if we closed (garbage collected?) a FD,
+        # opened a pipe and got the same int FD, and then some background
+        # task closed that same int FD again. FileObjectThread.close()
+        # goes through threadpool.apply(), which is supposed to be synchronous;
+        # make sure it is.
+        gevent.get_hub().threadpool.join()
+
+        # And collect any outstanding garbage, in case some resource is "leaking"
+        # (We have no indication that it is, but we're flailing wildly here to try
+        # to understand what could be happening)
+        gc.collect()
+        super(TestFileObjectThread, self).tearDown()
+
    # FileObjectThread uses os.fdopen() when passed a file-descriptor,
     # which returns an object with a destructor that can't be
     # bypassed, so we can't even create one that way
@@ -269,4 +286,5 @@ class TestTextMode(unittest.TestCase):
 
 
 if __name__ == '__main__':
+    sys.argv.append('-v')
     greentest.main()