Re-enable GCC 9.x Debian CI

[hartwork]

@Cropi what do you think?

[hartwork]

@Cropi any thoughts?

[Cropi]

@hartwork aren't the version check lines missing a closing quote? [[ "$(gcc -dumpversion) == 9.5.* ]] should be [[ "$(gcc -dumpversion)" == 9.5.* ]] ? The CI passed though. Also, on GCC 9+ gcc -dumpversion might return only the major version (9), which won't match the 9.5.* glob. Should gcc -dumpfullversion be used instead?

[hartwork]

@Cropi thanks for looking into it!

@hartwork aren't the version check lines missing a closing quote? [[ "$(gcc -dumpversion) == 9.5.* ]] should be [[ "$(gcc -dumpversion)" == 9.5.* ]] ? The CI passed though.

That's an interesting find — thanks! Fixed in a follow-up commit now.

Also, on GCC 9+ gcc -dumpversion might return only the major version (9), which won't match the 9.5.* glob. Should gcc -dumpfullversion be used instead?

I checked, it's returning 9.5.0 with this precise Docker image (gcc:9.5-bullseye). I believe we're good with plain -dumpversion.