pylint 2.16 fails on python 3.8.16

[andy-fox-rozettatech]

Bug description

pytlint fails itself on python 3.8.
3.9 and above seem OK

packages/pylint/checkers/imports.py", line 179, in _make_tree_defs
node[1] += files
TypeError: 'tuple' object does not support item assignment

Configuration

github actions (or elsewhere)
python 3.8.16

Collecting pylint
  Downloading pylint-2.16.0-py3-none-any.whl (530 kB)

Command used

pylint

Pylint output

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.8.16/x64/bin/pylint", line 8, in <module>
    sys.exit(run_pylint())
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/__init__.py", line 36, in run_pylint
    PylintRun(argv or sys.argv[1:])
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/lint/run.py", line 214, in __init__
    score_value = linter.generate_reports()
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/lint/pylinter.py", line 1149, in generate_reports
    sect = self.make_reports(self.stats, previous_stats)
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/reporters/reports_handler_mix_in.py", line 76, in make_reports
    r_cb(report_sect, stats, old_stats)
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/checkers/imports.py", line 981, in _report_external_dependencies
    dep_info = _make_tree_defs(self._external_dependencies_info().items())
  File "/opt/hostedtoolcache/Python/3.8.16/x64/lib/python3.8/site-packages/pylint/checkers/imports.py", line 179, in _make_tree_defs
    node[1] += files
TypeError: 'tuple' object does not support item assignment

Expected behavior

Not to fail ...

Pylint version

pylint 2.16.0

OS / Environment

ubuntu-latest on github actions

but also MacOS 13.2 etc

Additional dependencies

N/A

[Pierre-Sassoulas]

Thank you for opening the issue. Can you provide any information about the code pylint was run on when it crashed ?

[peanutsven]

Same here for python 3.7.3,

[DanielNoord]

Am I dumb or is this really strange?
https://github.com/PyCQA/pylint/blob/5c0084bb1465fcaed2c977266998360b9f2f5661/pylint/checkers/imports.py#L178-L179

How can node[1] be a tuple?

[mschmitzer]

How can node[1] be a tuple?

The problem is node being a tuple. The += is effectively turned into

tmp = node[1]
tmp += files
node[1] = tmp

and assigning the tuple item does not work.
The code was changed here , released in 2.16.

EDIT: Replacing the offending code with node[1].extend(files) would probably fix this.

[DanielNoord]

Yeah that should fix it. Are you able to provide a patch/PR?

[Pierre-Sassoulas]

If someone has a reproducer this would still be appreciated as this part of the code is not tested properly right now.

[mschmitzer]

If someone has a reproducer this would still be appreciated as this part of the code is not tested properly right now.

I found one. Interestingly, this does not seem related to the interpreter version, but hashseed dependant:

$ mkvirtualenv test
created virtual environment CPython3.10.6.final.0-64 in 53ms
...
$ pip install pylint
...
Successfully installed astroid-2.14.1 dill-0.3.6 isort-5.12.0 lazy-object-proxy-1.9.0 mccabe-0.7.0 platformdirs-2.6.2 pylint-2.16.0 tomli-2.0.1 tomlkit-0.11.6 typing-extensions-4.4.0 wrapt-1.14.1
$ touch bar.py
$ echo 'import bar' >foo.py
$ PYTHONHASHSEED='3172416510' pylint --rcfile /dev/null -r y foo.py
************* Module foo
foo.py:1:0: C0114: Missing module docstring (missing-module-docstring)
foo.py:1:0: C0104: Disallowed name "foo" (disallowed-name)
foo.py:1:0: W0611: Unused import bar (unused-import)
Traceback (most recent call last):
  File "/home/marc/.venv/test/bin/pylint", line 8, in <module>
    sys.exit(run_pylint())
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/__init__.py", line 36, in run_pylint
    PylintRun(argv or sys.argv[1:])
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/lint/run.py", line 214, in __init__
    score_value = linter.generate_reports()
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/lint/pylinter.py", line 1149, in generate_reports
    sect = self.make_reports(self.stats, previous_stats)
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/reporters/reports_handler_mix_in.py", line 76, in make_reports
    r_cb(report_sect, stats, old_stats)
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/checkers/imports.py", line 981, in _report_external_dependencies
    dep_info = _make_tree_defs(self._external_dependencies_info().items())
  File "/home/marc/.venv/test/lib/python3.10/site-packages/pylint/checkers/imports.py", line 179, in _make_tree_defs
    node[1] += files
TypeError: 'tuple' object does not support item assignment

EDIT: Sorry, I fixed up the example to include the --rcfile /dev/null but didn't adapt the output. Fixed now.