CI for older Linux versions

[tommag]

Hey Ben !

Following issue #57 and a number of people having trouble running Chataigne on Linux I've spent some time again on the CI.

Here is what I did :

• compile libssl 3 on a Debian 9 (Stretch) VM and add it to the AppImage
• setup a Docker image based on Debian Stretch that is used to build Chataigne. This is to be sure that the libc version requirement is not too high.

I've tested on the bleeding edge : the libssl 3 dependency is OK and Chataigne requires libc >= 2.27 which basically means Ubuntu 18.04 and higher.

I've tested with Debian 10 (Buster - released in 2019) and Ubuntu 22.10. Unfortunately older systems such as Debian 9 are not supported because Chataigne/JUCE uses C++17 and it would be even more complicated to have a C++17 compiler (gcc > 6) run on Debian 9. Not impossible but I've already spent a fair bit of time on it and it seems to me that it's a good balance to support 5-year old, currently supported OSes :) (Debian 9 is EOL already, Ubuntu 18.04 was supported until April 23).

I'd understand if you don't want to merge the PR as it complicates a bit the CI workflow (potential need to rebuild the Docker image). I'm willing to support the Linux CI in the future however :)

If you're OK with the PR maybe it would be interesting to publish a beta version and ask on the Discord if people can test it to see if there are issues before the next stable release ?

Cheers :)

[benkuper]

Hey and thanks :) would this risk affecting performance if it's been compiled for older systems ? I would prioritize performance over older OS, especially the ones reaching end of life

[tommag]

I think the only difference is that we're using an older version of gcc (GCC 8 released in 2018). Based on these benchmarks : https://www.phoronix.com/review/gcc8-gcc11-cxlx/2 it seems that the version of the compiler has very little real world impact on the compiled binary performance :

Personally I also find it important for Chataigne to be a lightweight tool running on "old" systems, especially on Linux where people may want to use older machines for small projects :)

[benkuper]

Done, thanks for the research and the work, as always ❤️