Beside the other issue I reported, there are a few other tweaks I want to try out, but I can't figure how to build this particular project:

1. I cloned the repository
2. I opened a terminal at the root, and ran ./gradlew genSourcesWithCfr
3. The task fails with this error:

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':common'.
> Could not resolve all files for configuration ':common:modImplementation'.
   > Could not find net.mehvahdjukaar:moonlight:1.20-2.9.11c.
     Searched in the following locations:
       <snip>
     Required by:
         project :common

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 13s

For the sake of experimentation, I went into all the build.gradle files and removed all lines the like of modImplmentation("net.mehvahdjukaar:xxx"). After that change, the genSources task was able to complete succesfully. (But obviously, the code would not compile.)

I think the build files are simply missing the repository for net.mehvahdjukaar ?

they are. thats on my local maven. You got to add it yourself, either like i have or using curse or modrinth maven or add the dep manually any other way

I think I got things working, but that was a bit unwieldy. Not knowing where to get the dependencies' correct version, I ended up needing to upgrade a bunch of other things.

If I give the "common" project a Moonlight jar that is specific to fabric/forge, I'm not gonna get any bad surprises, am I ?