Buck2: Our open source build system

No one seems to know how to do practical and useful build systems, so I write my own.

In particular the idea of writing something entirely generic that works for everything is a waste of time. The build system should be tailored to building your application in the way that matters to you and making the best of the resources that you have.

This sounds like a nightmare if you’re dealing with even single-digit numbers of projects - even just in my personal spare-time hobby projects, I have ~5 nodejs projects, ~5 php projects, ~5 rust projects, ~5 python projects - and I find myself wishing for a common build tool because right now, even if I only have one build system _per language_, that still means that eg migrating from travis to github actions meant that I needed to rewrite four separate build/test/deploy workflows...

I have 500 projects.

They're all made to follow the same conventions so neither of them specifies anything redundant.