Internal API _PyBytes_Join() is removed in Python 3.13

[musicinmybrain]

The internal CPython API function _PyBytes_Join() is removed in Python 3.13. You will need to find a substitute.

The most straightforward workaround is to just call the Python bytes.join method on the empty bytestring object we already have. Since this call happens only once at the end of GzipReader_readall, I suspect any added overhead should be negligible. I’ve tested this fix and will follow up with a PR.

See downstream Fedora Linux bug https://bugzilla.redhat.com/show_bug.cgi?id=2259627.

See also CPython issue python/cpython#106320 and specifically python/cpython#107144.

[rhpvorderman]

Let me think about this for a bit. The alternative is to use _PyBytes_Resize on a bytes object.

Thanks for reporting the issue.

[musicinmybrain]

Let me think about this for a bit. The alternative is to use _PyBytes_Resize on a bytes object.

OK! Since _PyBytes_Resize is documented, it is safe from this round of API removals even though it’s “private.”