ensure that we have an import_std configuration in the test-set

[burnpanck]

also, update flake8

[mpusz]

Ahh, I forgot to say that it also requires C++23+ to work 😢

Also, I do not know why a freestanding build failed.

FYI, I am providing a 3-day training from today, so I may be less responsive than usual.

[mpusz]

I've just changed the CI scripts (but not the generator) to account for C++23. They should also check for something like import_std_support when provided by the matrix.

[burnpanck]

the freestanding build failed because of an issue you seemed to have previously identified: In Debug builds, the CMakeCheckCompiler test fails due to a missing _main symbol. you had an "exclude" in the matrix, but "include" comes after, so we have to account for that in the generator. I forgot about that when I added that special "cxx_modules" subsample.

[burnpanck]

I might try to merge freestanding with the hosted conan, making this just another dimension of the matrix. I'll also extract the cxx_modules into its own dimension, and ensure all the unsupported combinations are skipped.

[burnpanck]

finally, I'll experiment with a truly random sample of configurations, together with a GitHub Actions "manual_trigger" with a user input to choose the random seed. I belive that should be possible.

[mpusz]

WOW! You are a true GitHub Actions Wizard! 😄 I would never come up with those solutions by myself. It is great to learn those things from you. Thanks!

[mpusz]

Also, it seems that there is some issue with contracts setting as it resolves to an empty string instead of "none" here:
https://github.com/mpusz/mp-units/actions/runs/11826393072/job/32952538814#step:15:3