gh-121489: Export private _PyBytes_Join() again

[cdce8p]

Followup from #121489 and #121646 (comment). Export the _PyBytes_Join() again until the new public PyBytes_Join() is added. If backported to 3.13, this would make transitioning easier.

This partially reverts #107144.

/CC @vstinner

• Issue: [C API] Private functions used by mypyc #121489

[cdce8p]

@encukou Seems we had a little misunderstanding here 😅 Sorry about that. Merging it into main and then backporting it to 3.13 was what I had in mind to begin with.

[encukou]

IMO this should be backported to 3.13 as the replacement is not available there.
I'll merge tomorrow if there are no objections.

[vstinner]

LGTM

[miss-islington-app]

Thanks @cdce8p for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13.
🐍🍒⛏🤖

[bedevere-app]

GH-122287 is a backport of this pull request to the 3.13 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot iOS ARM64 Simulator 3.x has failed when building commit aef95eb.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#builders/1380/builds/922) and take a look at the build logs.
4. Check if the failure is related to this commit (aef95eb) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#builders/1380/builds/922

Failed tests:

• test_socketserver

Failed subtests:

• test_ThreadingUnixDatagramServer - test.test_socketserver.SocketServerTest.test_ThreadingUnixDatagramServer

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last): File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/test/test_socketserver.py", line 228, in test_ThreadingUnixDatagramServerself.run_server(socketserver.ThreadingUnixDatagramServer, ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ socketserver.DatagramRequestHandler, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^self.dgram_examine) ^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/test/support/threading_helper.py", line 66, in decoratorreturn func(*args) File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/test/test_socketserver.py", line 133, in run_server testfunc(svrcls.address_family, addr) ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/test/test_socketserver.py", line 160, in dgram_examine buf = data = receive(s, 100) ~~~~~~~^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/test/test_socketserver.py", line 43, in receiveraiseRuntimeError("timed out on %r"% (sock,)) RuntimeError: timed out on <socket.socket fd=24, family=1, type=2, proto=0, laddr=./test_python_gi6ji1ee.sock> Traceback (most recent call last): File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/threading.py", line 1039, in _bootstrap_innerself.run() ~~~~~~~~^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/threading.py", line 990, in runself._target(*self._args, **self._kwargs) ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/socketserver.py", line 694, in process_request_threadself.handle_error(request, client_address) ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/socketserver.py", line 692, in process_request_threadself.finish_request(request, client_address) ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/socketserver.py", line 362, in finish_requestself.RequestHandlerClass(request, client_address, self) ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/socketserver.py", line 763, in __init__self.finish() ~~~~~~~~~~~^^ File "/Users/buildbot/Library/Developer/XCTestDevices/F05B2E02-3C3F-4FF7-A55F-11613958B0BB/data/Containers/Bundle/Application/99A3AB7F-A1D2-4792-B4C8-CC021997CCB1/iOSTestbed.app/python/lib/python3.14/socketserver.py", line 858, in finishself.socket.sendto(self.wfile.getvalue(), self.client_address) ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ConnectionResetError: [Errno 54] Connection reset by peer Warning -- threading_cleanup() failed to clean up threads in 1.0 seconds Warning -- before: thread count=0, dangling=1 Warning -- after: thread count=1, dangling=3 Warning -- Dangling thread: <Thread(<class 'socketserver.ThreadingUnixDatagramServer'> serving, started daemon 6115389440)> Warning -- Dangling thread: <Thread(Thread-2873 (process_request_thread), stopped 6132215808)> Warning -- Dangling thread: <_MainThread(MainThread, started 4372660800)> ERROR 

[mhsmith]

@freakboy3742: The iOS buildbot has failed this way a few times now. It looks like it's specific to the datagram server test, rather than a random failure of networking in general.

[freakboy3742]

@mhsmith Yes - I've seen that, but it appears to be a transient problem; subsequent builds work fine. I haven't been able to reproduce locally, but it appears to be related to load - it seems to coincide with longer than usual test runtimes.