python-nibabel fails to build with Python 3.15.0a6.

__________________________ test_DeterministicGzipFile __________________________

    def test_DeterministicGzipFile():
        with InTemporaryDirectory():
            msg = b"Hello, I'd like to have an argument."
    
            # No filename, no mtime
            with open('ref.gz', 'wb') as fobj:
                with GzipFile(filename='', mode='wb', fileobj=fobj, mtime=0) as gzobj:
                    gzobj.write(msg)
            anon_chksum = md5sum('ref.gz')
    
            with DeterministicGzipFile('default.gz', 'wb') as fobj:
                internal_fobj = fobj.myfileobj
                fobj.write(msg)
            # Check that myfileobj is being closed by GzipFile.close()
            # This is in case GzipFile changes its internal implementation
            assert internal_fobj.closed
    
>           assert md5sum('default.gz') == anon_chksum
E           AssertionError: assert 'abff1dfd2f8b...fe395999e3009' == 'e04e8bb89ad8...3ab57758a6ef2'
E             
E             - e04e8bb89ad8cb84ae93ab57758a6ef2
E             + abff1dfd2f8bbc2e7aefe395999e3009

nibabel/tests/test_openers.py:382: AssertionError
______________________ test_DeterministicGzipFile_fileobj ______________________

    def test_DeterministicGzipFile_fileobj():
        with InTemporaryDirectory():
            msg = b"Hello, I'd like to have an argument."
            with open('ref.gz', 'wb') as fobj:
                with GzipFile(filename='', mode='wb', fileobj=fobj, mtime=0) as gzobj:
                    gzobj.write(msg)
            ref_chksum = md5sum('ref.gz')
    
            with open('test.gz', 'wb') as fobj:
                with DeterministicGzipFile(filename='', mode='wb', fileobj=fobj) as gzobj:
                    gzobj.write(msg)
>           assert md5sum('test.gz') == ref_chksum
E           AssertionError: assert 'abff1dfd2f8b...fe395999e3009' == 'e04e8bb89ad8...3ab57758a6ef2'
E             
E             - e04e8bb89ad8cb84ae93ab57758a6ef2
E             + abff1dfd2f8bbc2e7aefe395999e3009

nibabel/tests/test_openers.py:435: AssertionError

I have no idea if this is a genuine issue or something related to Copr - opening the ticket to determine that.

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_64/10150483-python-nibabel/

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

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.