I am not convinced (yet) that using ini_set() to "fix" the configuration is the right course of action here.

In the meantime, I have updated the documentation to also suggest display_errors=On: sebastianbergmann/phpunit-documentation-english@b3b159c

alternative fix could be to suggest

<php>
  <ini name="display_errors" value="On"/>
</php>

in the configuration file when auto-generating.

but my gut feeling is, that people might miss a lot of obvious errors when not using the correct ini setting (which would mean lots of support tickets on phpunit).

we could also try to render a phpunit warning when display_errors=0, but atm phpunit crashes at the fatal error (so we would need a prepared error message in a shutdown function or similar)

pushed an alternative and less invasive fix, which does not change the config with ini_set(), but instead prepares a error message which gets printed on premature fatal errors

This should target the 12.3 branch, right?

yes

Cherry-picked into 12.3 and merged to main from there.