use ubuntu 20.04 in CI

[joergbrech]

After #29 was merged, Ubuntu 20.04 CI started failing at https://github.com/dlr-sc/tigl due to a glibc conflict. Ubuntu 22.04 builds seem to be uneffected. This PR is a desperate attempt to see if building the packages on Ubuntu 20.04 resolves this issue.

[rainman110]

You don't need to be desperate ;). I think it will work. You could even think of using an even older ubuntu, to have even larger support for different linux distros.

[joergbrech]

You don't need to be desperate ;). I think it will work. You could even think of using an even older ubuntu, to have even larger support for different linux distros.

Phew, I am relieved 😝

Currently, Github runners are Ubuntu 20.04 and 22.04 only, and I am guessing Ubuntu 20.04 will be dropped some time next year. To support older distros we would have to build everything in seperate docker containers.

For now, I am happy with a quick fix so that our TiGL CI works again. Supporting older distros could be implemented as part of another issue/pr.

[rainman110]

Supporting older distros could be implemented as part of another issue/pr.

I totally agree. I think it would be wise to use the same distros as conda-forge, maybe even the same docker container.
(quay.io/condaforge/linux-anvil-cos7-x86_64)

[joergbrech]

It turns out my desperation was completely appropriate ;)

#36 was needed to fix the issue.

[rainman110]

Very strange. Conda build comes with it's own GCC version 8 oder so. Cmake should use this compiler instead of the one provided by Ubuntu.

[joergbrech]

The native compiler on the GitHub runner is GCC 9.4. conda-build used 11.2. 🫤

https://github.com/DLR-SC/tigl-conda/actions/runs/7302577655/job/19901470530#step:8:219

https://github.com/actions/runner-images/blob/main/images%2Fubuntu%2FUbuntu2004-Readme.md