`sys.exit` unpacks its argument if it is a 0- or 1-element tuple

[dscorbett]

Bug report

Bug description:

The documentation of sys.exit says “The optional argument arg can be an integer giving the exit status (defaulting to zero), or another type of object. [...] If another type of object is passed, None is equivalent to passing zero, and any other object is printed to stderr and results in an exit code of 1.” This is no longer true for 0- and 1-element tuples in Python 3.12 and later. It acts like the argument is unpacked: sys.exit(()) is treated like sys.exit() and sys.exit((x,)) is treated like sys.exit(x).

$ python3.11 -c 'import sys; sys.exit(())'; echo $?
()
1

$ python3.12 -c 'import sys; sys.exit(())'; echo $?
0

$ python3.11 -c 'import sys; sys.exit((2,))'; echo $?
(2,)
1

$ python3.12 -c 'import sys; sys.exit((2,))'; echo $?
2

CPython versions tested on:

3.12, 3.13, CPython main branch

Operating systems tested on:

macOS

[terryjreedy]

Can you find the issue that made the change (git blame) and see if the behavior change was intended? If so, the doc should be changed.

[brianschubert]

This bisects to feec49c (#101607), cc @markshannon