Fatal Python error: Objects/frameobject.c:429 object at 0xb6c53304 has negative ref count -606348326 Current thread 0xb74bd700 (most recent call first): File "/home/beck/cpython/Lib/unittest/case.py", line 579 in run File "/home/beck/cpython/Lib/unittest/case.py", line 627 in __call__ File "/home/beck/cpython/Lib/unittest/suite.py", line 122 in run File "/home/beck/cpython/Lib/unittest/suite.py", line 84 in __call__ File "/home/beck/cpython/Lib/unittest/suite.py", line 122 in run File "/home/beck/cpython/Lib/unittest/suite.py", line 84 in __call__ File "/home/beck/cpython/Lib/unittest/suite.py", line 122 in run File "/home/beck/cpython/Lib/unittest/suite.py", line 84 in __call__ File "/home/beck/cpython/Lib/test/support/__init__.py", line 1674 in run File "/home/beck/cpython/Lib/test/support/__init__.py", line 1775 in _run_suite File "/home/beck/cpython/Lib/test/support/__init__.py", line 1809 in run_unittest File "/home/beck/cpython/Lib/test/regrtest.py", line 1279 in test_runner File "/home/beck/cpython/Lib/test/regrtest.py", line 1280 in runtest_inner File "/home/beck/cpython/Lib/test/regrtest.py", line 978 in runtest File "/home/beck/cpython/Lib/test/regrtest.py", line 532 in main File "/home/beck/cpython/Lib/test/regrtest.py", line 1564 in main_in_temp_cwd File "/home/beck/cpython/Lib/test/regrtest.py", line 1589 in File "/home/beck/cpython/Lib/runpy.py", line 85 in _run_code File "/home/beck/cpython/Lib/runpy.py", line 170 in _run_module_as_main Traceback (most recent call last): File "/home/beck/cpython/Lib/runpy.py", line 170, in _run_module_as_main "__main__", mod_spec) File "/home/beck/cpython/Lib/runpy.py", line 85, in _run_code exec(code, run_globals) File "/home/beck/cpython/Lib/test/__main__.py", line 3, in regrtest.main_in_temp_cwd() File "/home/beck/cpython/Lib/test/regrtest.py", line 1564, in main_in_temp_cwd main() File "/home/beck/cpython/Lib/test/regrtest.py", line 738, in main raise Exception("Child error on {}: {}".format(test, result[1])) Exception: Child error on test_contextlib: Exit code -6