[issue44280] unittest filters out too many assertion stack frames from context/cause chains

Change by Peter Hawkins : -- components: +Library (Lib) type: -> behavior ___ Python tracker <https://bugs.python.org/issue44280> ___ ___ Python-bugs-list mai

[issue44280] unittest filters out too many assertion stack frames from context/cause chains

New submission from Peter Hawkins : Example repro: ``` import unittest def d(): assert 2 == 3 def c(): d() def b(): c() def a(): try: b() except Exception as e: assert 1 == 2 class MyTest(unittest.TestCase): def testException(self): a() if __name__ == '__m