Bug 2424590

Summary: borgbackup fails to build with Python 3.15: ValueError: badly formed help string
Product: [Fedora] Fedora Reporter: Karolina Surma <ksurma>
Component: borgbackupAssignee: Felix Schwarz <fschwarz>
Status: CLOSED WORKSFORME QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rawhideCC: fschwarz, ksurma, mhroncok
Target Milestone: ---   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-02-14 12:36:35 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2412434    

Description Karolina Surma 2025-12-23 13:24:44 UTC
borgbackup fails to build with Python 3.15.0a3.

4 tests errored with the same issue:

_________________ ERROR collecting borg/testsuite/archiver.py __________________
/usr/lib64/python3.15/argparse.py:1792: in _check_help
    formatter._expand_help(action)
/usr/lib64/python3.15/argparse.py:695: in _expand_help
    return help_string % params
           ^^^^^^^^^^^^^^^^^^^^
E   TypeError: %o format: an integer is required, not str

The above exception was the direct cause of the following exception:
borg/testsuite/archiver.py:5344: in <module>
    @pytest.mark.parametrize('command, parser', list(get_all_parsers().items()))
                                                     ^^^^^^^^^^^^^^^^^
borg/testsuite/archiver.py:5321: in get_all_parsers
    parser = Archiver(prog='borg').build_parser()
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
borg/archiver.py:3850: in build_parser
    subparser.add_argument('--stdin-mode', metavar='M', dest='stdin_mode', type=lambda s: int(s, 8), default=STDIN_MODE_DEFAULT,
/usr/lib64/python3.15/argparse.py:1600: in add_argument
    self._check_help(action)
/usr/lib64/python3.15/argparse.py:1794: in _check_help
    raise ValueError('badly formed help string') from exc
E   ValueError: badly formed help string

https://docs.python.org/3.15/whatsnew/3.15.html

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.15/fedora-rawhide-x86_64/09935190-borgbackup/

For all our attempts to build borgbackup with Python 3.15, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.15/package/borgbackup/

Testing and mass rebuild of packages is happening in copr.
You can follow these instructions to test locally in mock if your package builds with Python 3.15:
https://copr.fedorainfracloud.org/coprs/g/python/python3.15/

Let us know here if you have any questions.

Python 3.15 is planned to be included in Fedora 45.
To make that update smoother, we're building Fedora packages with all pre-releases of Python 3.15.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires),
so if this package is required a lot, it's important for us to get it fixed soon.

We'd appreciate help from the people who know this package best,
but if you don't want to work on this now, let us know so we can try to work around it on our side.

Comment 1 Felix Schwarz 2026-02-14 12:36:35 UTC
As far as I can see building works at least with Python 3.15.0a5 (https://copr.fedorainfracloud.org/coprs/g/python/python3.15/build/10021594/) on COPR and on my local machine.

I'm closing this bug report but feel free to reopen in case I missed something.