INTERNALERROR: Unknown entry type returned: TraceLastReprEntry

[filbranden]

I'm seeing INTERNALERROR: Unknown entry type returned: TraceLastReprEntry with a long long unreadable traceback when running tests for python-attrs/attrs that produce type checker failures.

This is the traceback of the exception in pytest:

INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/xdist/workermanage.py", line 414, in process_from_remote
INTERNALERROR>     rep = self.config.hook.pytest_report_from_serializable(
INTERNALERROR>           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/pluggy/_hooks.py", line 513, in __call__
INTERNALERROR>     return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
INTERNALERROR>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/pluggy/_manager.py", line 120, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/pluggy/_callers.py", line 139, in _multicall
INTERNALERROR>     raise exception.with_traceback(exception.__traceback__)
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/pluggy/_callers.py", line 103, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>           ^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 460, in pytest_report_from_serializable
INTERNALERROR>     return TestReport._from_json(data)
INTERNALERROR>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 226, in _from_json
INTERNALERROR>     kwargs = _report_kwargs_from_json(reportdict)
INTERNALERROR>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 593, in _report_kwargs_from_json
INTERNALERROR>     reprtraceback = deserialize_repr_traceback(
INTERNALERROR>                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 578, in deserialize_repr_traceback
INTERNALERROR>     deserialize_repr_entry(x) for x in repr_traceback_dict["reprentries"]
INTERNALERROR>     ^^^^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 573, in deserialize_repr_entry
INTERNALERROR>     _report_unserialization_failure(entry_type, TestReport, reportdict)
INTERNALERROR>   File "/tmp-attrs/attrs/.tox/py312-tests/lib/python3.12/site-packages/_pytest/reports.py", line 241, in _report_unserialization_failure
INTERNALERROR>     raise RuntimeError(stream.getvalue())

It looks like deserialize_repr_entry in pytest code base makes a specific check for the entry type and only supports "ReprEntry" or "ReprEntryNative", otherwise it throws this RuntimeError.

It seems updating pytest_mypy_plugins/item.py to set repr_tb_entry = ReprEntry(...) also prevents the error from happening.

In order to reproduce this issue, clone the python-attrs/attrs repo, then modify tests/test_mypy.yml to introduce any typing error, then run tox or tox -e py312-tests (quicker), the error message is very long and almost impossible to read!

Thanks!