Fix: Handle the messed-up status of packages on Ubuntu derivatives

[ipspace]

Pop!_OS supposedly has the 'linux-modules-extra' package, but rejects to install it with a weird error messsage that doesn't even produce a proper exit code. This patch uses a slightly different approach to figuring out if the package is there to be installed.

Tested on Pop!_OS 22.04, Ubuntu 24.04 and Debian Bookworm

[ipspace]

Hey @zalekz, this should fix the last remaining problem in #2441. Could you please verify it? Thank you!

[zalekz]

Hey @zalekz, this should fix the last remaining problem in #2441. Could you please verify it? Thank you!

@ipspace : Sorry for being late, I see that the changes have already been merged, but yes, I can also confirm that everything now installs on Pop!_OS 22.04 flawlessly using the updated scripts from the current dev branch, those with apt-cache search instead of apt-cache show. After the installation the user is suggested to reboot the system though, so all the necessary services are started automatically.. The clab and libvirt tests are successful then after a system restart. Many thanks!

[zalekz]

$SUDO apt-get -y $FLAG_APT install python3 python3-setuptools ifupdown python3-pip curl $EXTRA

Perhaps, there is no need in that $EXTRA variable on this line anymore

[ipspace]

Yeah, that one should go out (the next time we're changing this script ;)

[ipspace]

I can also confirm that everything now installs on Pop!_OS 22.04 flawlessly using the updated scripts from the current dev branch, those with apt-cache search instead of apt-cache show.

Thanks a million for the confirmation!