workflows/tests.yml: fix Gentoo testing

[Nowa-Ammerlaan]

Add --autounmask-continue to tell portage to make whatever configuration changes it deems necessary, and then continue.

Add --getbinpkg to fetch prebuilt packages from the binary host to speed things up a bit.

[evelikov]

Must admit I don't quite follow the --archive to --preserve=all change. The former is -dR --preserve=all, where -d is --preserve=links and -R is recursive were we copy a single file.

Please add a small note with rational in the commit message.

[Nowa-Ammerlaan]

Must admit I don't quite follow the --archive to --preserve=all change. The former is -dR --preserve=all, where -d is --preserve=links and -R is recursive were we copy a single file.

Please add a small note with rational in the commit message.

To be honest, I don't understand why this fixes the problem. Somehow it fails with --recursive, but it does not make sense because it should be a single file. In any case we don't need --recursive because it should always be a single file.

[evelikov]

Ack, seems like I broke it with my push yesterday. Sorry for the mess and thanks for fixing it ❤️

[Nowa-Ammerlaan]

Alright finished! We're all green again now. Made the Gentoo tests a lot faster in the process by fetching binary packages and using the prebuilt initramfs/uki instead of generating one locally in the container. It now completes in just 3 minutes.

[evelikov]

Amazing, thanks again 🚀

[evelikov]

Out of curiosity:

How does Gentoo ignore the kernel config toggle about the module compression? Does Gentoo's tooling not use make modules_install or perhaps it's invoked in particular way?

[Nowa-Ammerlaan]

How does Gentoo ignore the kernel config toggle about the module compression? Does Gentoo's tooling not use make modules_install or perhaps it's invoked in particular way?

We configure the kernel with support for xz compressed modules, then patch the build system to skip the actual compression in make modules_install. This allows us to distribute a kernel that supports both compressed and uncompressed modules, while leaving the modules in the package tarball uncompressed. This is more efficient compression wise because xz compressing a bunch of uncompressed files results in a smaller tarball compared to xz compressing a bunch of files that are each individually already xz compressed. In the install phase the modules are then xz compressed or not depending on whether the user enabled USE=modules-compress (the default is disabled).