Failure on Ubuntu 24.04

[kleisauke]

The default CodeQL setup in the libvips repository appears to fail after the after the ubuntu-latest image was migrated to Ubuntu 24.04. For example, compare the following runs:
https://github.com/libvips/libvips/actions/runs/12577488911/job/35054987879#step:1:4
versus:
https://github.com/libvips/libvips/actions/runs/12683554993/job/35350821841#step:1:4

According to CodeQL's system requirements, Ubuntu 24.04 is not (yet?) supported. I suspect this incompatibility is also the root cause of the failure, as indicated by the following error in CodeQL CLI v2.20.0:

[build-stderr] cpp/autobuilder: deptrace not supported in ubuntu 24.04

^{(see: https://github.com/libvips/libvips/actions/runs/12683554993/job/35350821841#step:5:74)}

This specific error message is no longer displayed in CodeQL CLI v2.20.1; however, the workflow still appears to fail. For example:
https://github.com/libvips/libvips/actions/runs/12802008925/job/35692408039#step:6:70

For additional context, I've rerun the latest failed CodeQL workflow with debugging enabled:
https://github.com/libvips/libvips/actions/runs/12802008925/job/35775146400

[redsun82]

Hi @kleisauke, thanks for reaching out.

The system requirements might be out of date at the moment, I would expect analysis to indeed work on 24.04. We did indeed have C/C++ autobuild not working to its full potential in 2.20.0 but as you noticed that was fixed with 2.20.1.

I will have a look. What I also find surprising is that the final error message in the analyze step mentions that CodeQL wasn't able to build any of the code, even though the autobuild step was successful.

[redsun82]

Hmm, seems like for some reason the tracer gave up on tracing the build (there's a bunch of CODEQL_TRACER_LANGUAGES is empty messages in the build_tracer.log file. That is weird, and I will do some more investigation on Monday. I can confirm this should work on 24.04, we even have our own C++ scan running on that (see https://github.com/github/codeql/actions/workflows/cpp-swift-analysis.yml).

[kleisauke]

If it helps, here's another project experiencing similar symptoms:
https://github.com/mm2/Little-CMS/actions/runs/12829208512/job/35774821548

Additionally, I noticed that the deptrace.log file contains numerous client closed connection messages, but I'm uncertain whether this is a real issue.

The system requirements might be out of date at the moment, I would expect analysis to indeed work on 24.04.

Thanks for clarifying! Good to know that CodeQL ought to work on Ubuntu 24.04.