It occurs to me that the first steps I take in most new-to-me established projects are basically magic - I'm looking for specific shell commands that the other dev(s) use to perform certain actions: build, run, test, deploy, etc. What's more, there are often undocumented environment dependencies - env vars that need to be set, certain executables that must be installed on the dev's system and in the path, etc.

> It looks opaque, but it can be understood.

I don't think "magic" in this sense means "cannot be understood" - only that it's incomprehensible at some point, and it's performed without understanding to achieve the desired result.