Extraneous error output when process exits after using subinterpreters

[a-reich]

Bug report

Bug description:

I opened an issue earlier on the repo for the PyPI backport, but now that PEP 734 is implemented (🎉!) I am doing so here.

Reproducer:

>>> from concurrent import interpreters
>>> interp1 = interpreters.create()
>>> interp1.close() # same output occurs without this
>>> exit
Exception ignored while calling deallocator <function Interpreter.__del__ at 0x7308402c8460>:
Traceback (most recent call last):
  File "/usr/lib/python3.14/concurrent/interpreters/__init__.py", line 146, in __del__
  File "/usr/lib/python3.14/concurrent/interpreters/__init__.py", line 162, in _decref
TypeError: catching classes that do not inherit from BaseException is not allowed

I am on release 3.14.0b3 installed as an ubuntu distribution, running on WSL.

CPython versions tested on:

3.14

Operating systems tested on:

Linux

[brianschubert]

Also reproduces on master, cc @ericsnowcurrently

[sobolevn]

This happens because InterpreterNotFoundError is already None at this point:

cpython/Lib/concurrent/interpreters/__init__.py

Lines 156 to 163 in 1ddfe59

	def _decref(self):
	if not self._ownsref:
	return
	self._ownsref = False
	try:
	_interpreters.decref(self._id)
	except InterpreterNotFoundError:
	pass