Updating a specific dependency

[zhiltsov-max]

Hi, our project uses pip-compile-multi for Python dependency management. Basically, we have a requirements.in, which is used to generate a locked requirements.txt file. There are several related issues in the current pipeline. I'm looking for advice on how to solve them better.

1. If we need to change a dependency, e.g. add a new one, running pip-compile-multi (and so underlying pip-compile) leads to building all the dependencies in all the files. Would it be possible to just add a package without rebuilding everything (e.g. check the new package deps against the existing requirements.txt, update what's necessary, update the file hash) or at least avoid rebuilding some packages (which may not be available on some platforms because of missing build deps, binaries, libs etc.)? I tried using --upgrade-package "<new package>" and --no-upgrade, but it didn't seem to help.
2. One of the dependencies in our project, namely av, removed binary wheels from pypi at some point, so we're building the package ourselves. The package build depends on Cython being < 3.0.0, so listing it in the requirements.in doesn't help.
3. There's a possible solution with the pip-compile command - supplying --pip-args "--no-build-isolation 'av==9.2.0'" seems to help with building the av package, after the build environment is set up before running the command. I could find a similar option in pip-compile-multi, but it seems to be global for all the packages.