Using BinaryBuilder to run a CMakeFile for a local library

I’m kinda confused about the usage of BinaryBuilder.jl

I can point it to the source I want to build; i.e:

name = "libfoo"
version = v"1.0.1"
sources = [
    ArchiveSource("<url to source tarball>", "sha256 hash"),

Yet I already have my library installed, and can reach it by parsing ENV.
My question is: What do I need to fill in for the sources? I can re-download my sources, but since I already have my library installed, that’s not necessary. Is it enough to just to point the sources array to my CMakeLists by parsing ENV?

You can use a DirectorySource. Just make sure the directory doesn’t recursively include your current directory or the directory where the build_tarballs.jl script is, otherwise you open a black hole