[tae898]

tests/test_python_function_interrupt.py::test_sigint_during_a_query_that_calls_python_is_a_keyboard_interrupt failed every time (assert 0 >= 1, 20 of 20) on a runner that starts pytest as a background job, on both the 26.10.2 and the 26.11.1-SNAPSHOT native engine, and passed in CI. The binding is fine; the test relied on a handler Python does not always install.

Cause: Python installs signal.default_int_handler at startup only when SIGINT is not ignored. A shell runs an asynchronous command (cmd &, no job control) with SIGINT set to SIG_IGN, and the setting survives exec, so the pytest process starts with getsignal(SIGINT) == SIG_IGN. os.kill(os.getpid(), SIGINT) is then dropped, no query is interrupted, and the test runs the full 22 to 25 s of eight uninterrupted queries before it fails.

Evidence, same wheel and test, one launch path changed at a time:

launch of the pytest process	getsignal(SIGINT) in the test	result
inherited from the agent shell, under quiet_build.sh (systemd scope, taskset, nice)	default_int_handler	passed in 2.3 s
bash -c "... & wait"	SIG_IGN (SigIgn bit 0x2 set in /proc/self/status)	failed in 24.7 s
same & launch, default_int_handler installed first	default_int_handler	passed in 2.2 s

So the scope, nice and taskset layers do not matter, and the native default-handler path (_dispatch entry, interrupt note, error reply, KeyboardInterrupt) works: the test passes there with the handler in place. test_sigint_loop_in_a_fresh_process_ends_cleanly and test_sigint.py already install the handler for their child processes for the same reason.

Fix: a default_sigint_handler fixture installs signal.default_int_handler for the test and restores the old handler. tests/README.md gets a short section on how to check a runner (grep SigIgn /proc/self/status, bit 0x2).

Checked on the laptop with the final file, pytest started as an & job (SIGINT ignored), tests/test_python_function_interrupt.py whole:

• before: 0 of 20 runs passed the test on 26.11.1-SNAPSHOT and 0 of 20 on 26.10.2
• after: 26 of 26 runs of the file pass (3 passed, 2 skipped each) on 26.11.1-SNAPSHOT and 26 of 26 on 26.10.2 (20 + 6 per wheel; the 6 are the final file after formatting)

scripts/check_no_embedded_name.py --root . is clean and black reports nothing on the changed lines.

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