[geezerjay]

> a way to tell it where your dependencies are installed(like cmake’s CMAKE_PREFIX_PATH).

That's not how dependencies are discovered in cmake. Dependencies are added with calls to find_package, and if you have to include dependencies that don't install their cmake or even pkconfig module then you add your own Find<dependency>.cmake file to the project to search for it, set targets, and perform sanity checks.

[humanrebar]

That's not entirely true, CMAKE_PREFIX_PATH is used in find_package and find_library calls.