Restore support for older glibc versions in CI builds

[LinqLover]

For example, recent builds no longer work on Ubuntu 20 due to missing glibc version, which is a bit inconvenient. Ubuntu 20 Pro is still supported until 2030, so that's a valid platform IMHO.

[marceltaeumel]

This is probably a wont fix because we have to stick to the GitHub Actions runners we can use, for free by the way. However, we can add custom OSVM builds to any released VM later on.

I would love to, e.g., still use a runner with Ubuntu 18.04 and an older GLIBC. We just have no access to such a runner.

https://docs.github.com/en/actions/reference/runners/github-hosted-runners#standard-github-hosted-runners-for-public-repositories

[LinqLover]

Couldn't we run an older Docker container in the GitHub workflow?

    runs-on: ubuntu-22.04
    container:
      image: ubuntu:18.04

Plus maybe we need to install some packages in the docker, but ChatGPT makes me think it should be an almost drop-in replacement.

[marceltaeumel]

Couldn't we run an older Docker container in the GitHub workflow?

Is this a supported feature or a hallucination of ChatGPT? Last I read was that docker-format actions are legacy. But I could be mistaken about the whole docker support in GitHub Action runners.

[LinqLover]

It is documented without any note for deprecation: https://docs.github.com/en/actions/how-tos/write-workflows/choose-where-workflows-run/run-jobs-in-a-container?utm_source=chatgpt.com Importantly, this only runs single steps in the container, not the entire job, so the runner itself still runs on the host. Maybe I can spike this if it is not urgent. :-)

[marceltaeumel]

Thanks. If it works, it should be part of our extra monthly builds because this will likely take extra build time and is of limited use to have as a nightly or on-push build.

[Kreijstal]

you could just test if it works for musl, then that is truly portable