Different results with -j4 and -j8 #4356
Description
I'm not sure if this is a duplicate of #2573 or #374 because I don't know if those are particular to the specific checks they mention.
Steps to reproduce
git clone https://github.com/nedbat/coveragepy; cd coveragepygit checkout 50cc68846fpip install toxtox -e lint --notest.tox/lint/bin/python -m pylint --notes= -j 4 coverage tests doc ci igor.py setup.py __main__.py- No violations are reported
.tox/lint/bin/python -m pylint --notes= -j 8 coverage tests doc ci igor.py setup.py __main__.py
************* Module coverage.pytracer coverage/pytracer.py:140 E: self.should_start_context is not callable (not-callable) coverage/pytracer.py:165 E: self.should_trace is not callable (not-callable) coverage/pytracer.py:166 E: 'self.should_trace_cache' does not support item assignment (unsupported-assignment-operation) coverage/pytracer.py:171 E: Value 'self.data' doesn't support membership test (unsupported-membership-test) coverage/pytracer.py:172 E: 'self.data' does not support item assignment (unsupported-assignment-operation) coverage/pytracer.py:173 E: Value 'self.data' is unsubscriptable (unsubscriptable-object) coverage/pytracer.py:259 E: self.warn is not callable (not-callable) A different manifestation of what might be the same underlying cause: in my CI, running -j4, I get occasional failures with these same violations reported.
Expected behavior
The number of processes shouldn't change the results, only the performance.
pylint --version output
Result of pylint --version output:
$ .tox/lint/bin/python -m pylint --version pylint 2.7.4 astroid 2.5.3 Python 3.8.8 (default, Mar 21 2021, 13:50:20) [Clang 12.0.0 (clang-1200.0.32.29)]