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Changes in Python 3.14.3 break cmd2 #1570
Description
Error:
______________________________ ERROR collecting tests/test_argparse_completer.py _______________________________
tests/test_argparse_completer.py:42: in <module>
class ArgparseCompleterTester(cmd2.Cmd):
tests/test_argparse_completer.py:303: in ArgparseCompleterTester
arg_tokens_subparser = arg_tokens_parser.add_subparsers(dest='subcommand')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
cmd2/argparse_custom.py:1509: in add_subparsers
return super().add_subparsers(**kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
../../../.local/share/uv/python/cpython-3.14.3-macos-aarch64-none/lib/python3.14/argparse.py:1968: in add_subparsers
formatter.add_usage(None, positionals, groups, '')
.venv/lib/python3.14/site-packages/rich_argparse/_argparse.py:232: in add_usage
usage_text = _strip_codes(self._format_usage(usage, actions, groups, prefix=prefix))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
cmd2/argparse_custom.py:1172: in _format_usage
format_actions = self._format_actions_usage
^^^^^^^^^^^^^^^^^^^^^^^^^^
E AttributeError: 'Cmd2HelpFormatter' object has no attribute '_format_actions_usage'
=========================================== short test summary info ============================================
ERROR tests/test_argparse_completer.py - AttributeError: 'Cmd2HelpFormatter' object has no attribute '_format_actions_usage'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=============================================== 1 error in 0.18s ===============================================
Activity
github-actions commentedon Feb 4, 2026
🤖 Hi @tleonhardt, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.
tleonhardt commentedon Feb 4, 2026
Whatever the fix is we'll have to make on both the
mainand3.xbranches.tleonhardt commentedon Feb 5, 2026
I'm thinking we actually need to create an issue for rich_argparse to make sure that module properly supports Python 3.14.3 in general and for the
RichHelpFormatterin particular.Another option might be to remove some of our custom formatting.
tleonhardt commentedon Feb 5, 2026
PR #1571 addresses this issue for the 3.x branch. Once that merges in, we'll need to cherry-pick changes to a branch intended to marge into
main.[-]argparse changes in Python 3.14.3 break cmd2[/-][+]Changes in Python 3.14.3 break cmd2[/+]