Issue #26563:
* Add _PyGILState_GetInterpreterStateUnsafe() function: the single
PyInterpreterState used by this process' GILState implementation.
* Enhance _Py_DumpTracebackThreads() to retrieve the interpreter state from
autoInterpreterState in last resort. The function now accepts NULL for interp
and current_tstate parameters.
* test_faulthandler: fix a ResourceWarning when test is interrupted by CTRL+c
Issue #26563: Debug hooks on Python memory allocators now raise a fatal error
if functions of the PyMem_Malloc() family are called without holding the GIL.
This reverts most of revision 3092cf163eb4. The change worked on x86
architectures, but did not work on ARM, probably due to extra ABI flags in
the ldconfig output.
Issue #26538: libregrtest: Fix setup_tests() to keep module.__path__ type
(_NamespacePath), don't convert to a list.
Add _NamespacePath.__setitem__() method to importlib._bootstrap_external.
* Add Lib/test/signalinterproctester.py
* Don't disable the garbage collector anymore
* Don't use os.fork() with a subprocess to not inherit existing signal handlers
or threads: start from a fresh process
* Don't use UNIX kill command to send a signal but Python os.kill()
* Use a timeout of 10 seconds to wait for the signal instead of 1 second
* Always use signal.pause(), instead of time.wait(1), to wait for a signal
* Use context manager on subprocess.Popen
* remove code to retry on EINTR: it's no more needed since the PEP 475
* remove unused function exit_subprocess()
* Cleanup the code
Issue #26516:
* Add PYTHONMALLOC environment variable to set the Python memory
allocators and/or install debug hooks.
* PyMem_SetupDebugHooks() can now also be used on Python compiled in release
mode.
* The PYTHONMALLOCSTATS environment variable can now also be used on Python
compiled in release mode. It now has no effect if set to an empty string.
* In debug mode, debug hooks are now also installed on Python memory allocators
when Python is configured without pymalloc.
Revert:
"Always test datetime.strftime("%4Y")
Issue #13305: Always test datetime.datetime.strftime("%4Y") for years < 1900."
In fact, strftime("%4Y") fails on most platforms.
