> Some people will tell you "yeah bro just use docker with this and that and you will have a reproducible build system everywhere", but the thing is - I do not want to learn a completely unrelated tool and spend hours writing some scripts just to be able to continue working on my project
You're working with some seriously hairy technologies, dealing with very knotty compatibility issues, and you don't want to learn... Docker?
I find this odd because it's relatively simple (certainly much simpler that a lot of what you're currently dealing with), well documented, has a very small, simple syntax and would probably solve your problems with much less effort than setting up a third development machine.
Docker solves the problems in some cases. However it forces you to ignore those knotty compatibility issues which is limiting. (You can't run on *BSD, Mac, windows... if you use docker) As such for many docker is not in the list of acceptable answers - in particular any open source project should consider docker not an option to solve their problems.
My understanding of the post I was replying to was that the compatibility issues were due to different versions of Linux having different clang versions. If I've understood correctly then Docker is highly likely to be a good solution.
> any open source project should consider docker not an option to solve their problem
That's generalising far too much.