Class sigaction

src/foundation/subprocess.c:889–889

 * exec-failure fallback below, so this stays compiled everywhere. */
static void cbm_posix_reset_child_signals(void) {
    struct sigaction action = {0};
    action.sa_handler = SIG_DFL;
    (void)sigemptyset(&action.sa_mask);
    for (int sig = 1; sig < NSIG; sig++) {