Thank you @GromNaN.

This change causes Segmentation fault when Xdebug path coverage is enabled.

I really can't blame this change, because in my case $commandSignals is empty, but foreach call itself causes segmentation fault much further down the line. (Removing foreach solves my problem).

Also this change only causes segmentation fault when used in combination with Codeception 5 and PHPUnit's main branch.
I can't create smaller sample than this: https://github.com/Naktibalda/codeception-segfault
Xdebug bug report https://bugs.xdebug.org/view.php?id=2108
Similar segmentation fault was caused and quickly fixed by moving signal code back in August.

It might be possible to prevent this issue by wrapping the foreach in an if ($commandSignals) { ... } but that will not solve it when command signal are actually used.