import unittest
import sys
import gc

def foo():
    try:
        raise RuntimeError("foo 1")
    except RuntimeError:
        raise ValueError("foo 2")

class TestCase(unittest.TestCase):
    def test_foo(self):
        context = self.assertRaises(ValueError)
        with context:
            foo()
        # debug code
        if sys.version_info[:2] >= (3, 2):
            print("--------------------------")
            e1 = context.exception
            print(gc.get_referents(e1))
            print(repr(e1.__context__))
            e2 = e1.__context__
            print(gc.get_referents(e2))
            print(repr(e2.__traceback__))
            print("--------------------------")

def test_main():
    gc.disable()
    gc.set_debug(gc.DEBUG_LEAK)
    try:
        unittest.main()
    finally:
        print("===========================")
        gc.collect()
        print("===========================")

if __name__ == '__main__':
    test_main()