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3.13 Regression: inspect.getsource() returns incorrect source code #122981
Description
Bug report
Bug description:
In Python 3.13rc1, inspect.getsource() sometimes returns a "random" line for some objects.
For example, here's ssl.AlertDescription:
$ docker run --rm python:3.13-rc python -c "import inspect, ssl; print(inspect.getsource(ssl.AlertDescription))"
super().shutdown(how)This line is likely https://github.com/python/cpython/blob/v3.13.0rc1/Lib/ssl.py#L1334.
In contrast, on 3.12 and below, this raises an OSError (not ideal but also not wrong):
$ docker run --rm python:3.12-rc python -c "import inspect, ssl; print(inspect.getsource(ssl.AlertDescription))"
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/local/lib/python3.12/inspect.py", line 1285, in getsource
lines, lnum = getsourcelines(object)
^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/inspect.py", line 1267, in getsourcelines
lines, lnum = findsource(object)
^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.12/inspect.py", line 1112, in findsource
raise OSError('could not find class definition')
OSError: could not find class definitionI'm not sure why this is happening, but it also affects pytest.PytestAssertRewriteWarning and pluggy.PluggyTeardownRaisedWarning, which both extend custom classes that override __module__.
CPython versions tested on:
3.8, 3.9, 3.10, 3.11, 3.12, 3.13
Operating systems tested on:
Linux
Activity
devdanzin commentedon Aug 14, 2024
Bisected to 153b3f7, introduced by #118475.
It happens because class
ssl.AlertDescriptionnow has a__firstlineno__attribute, and that is erroneously interpreted as a line number in ssl.py. It shares the same line number (1334) with other classes, likeSSLErrorNumber, created viaIntEnum._convert_. This line number corresponds toIntEnum's line number in enum.py instead.So ISTM the issue is that the construction of
__firstlineno__for these classes is capturing the line number of the class generator definition instead of the class creation site.cc @serhiy-storchaka
pythongh-122981: Fix inspect.getsource() for generated classes with P…
serhiy-storchaka commentedon Aug 14, 2024
Thank you for your report @mhils. I agree with @devdanzin analysis.
__firstlineno__is not set for these enum classes, but inherited from the base class. There is a test for generated class, but it does not have a base class that has__firstlineno__.#123001 should fix this.
pythongh-122981: Fix inspect.getsource() for generated classes with P…
mhils commentedon Aug 14, 2024
Awesome - thank you two for getting to the bottom of this with lightning speed! ⚡🍰 😃
gh-122981: Fix inspect.getsource() for generated classes with Python …
pythongh-122981: Fix inspect.getsource() for generated classes with P…
pythongh-122981: Fix inspect.getsource() for generated classes with P…
[3.13] gh-122981: Fix inspect.getsource() for generated classes with …
mhils commentedon Sep 10, 2024
Thank you two again! I can confirm that the issue is fixed now for
ssl.AlertDescriptionwith 3.13rc2. Unfortunately our smoke tests still show a very similar error in this case here:$ docker run --rm python:3.13.0rc2 bash -c \ 'pip install pluggy==1.5.0; python -c "import inspect, pluggy; print(inspect.getsource(pluggy.PluggyTeardownRaisedWarning))"' [...] "PluginManager",docker run --rm python:3.12 bash -c \ 'pip install pluggy==1.5.0; python -c "import inspect, pluggy; print(inspect.getsource(pluggy.PluggyTeardownRaisedWarning))"' [...] OSError: could not find class definition(https://github.com/mitmproxy/pdoc/actions/runs/10772390037/job/29935976461?pr=730)
Would you like me to file a new issue, or do we keep it here?
Thanks! 😃
serhiy-storchaka commentedon Sep 11, 2024
pluggy.PluggyTeardownRaisedWarningis not the part of the stdlib, so I cannot say what exactly happened, but this may be related to #123339.