Linking external libraries into Transforms

How do I link external libraries into a Transform?

We are currently using the multiprecision math libraries to perform a tricky mathematical decomposition within the language we are working on. Unfortunately, it is unclear how to add mpfr, et al into the build. The decomposition is leveraged from another project and the ordering is finicky when it comes to compiling as well.

I have tried compiling the other project into a static library that can be included, which should make the linking more stable (i.e., statically build the library, include the .h files, place into Release+Asserts/lib/…, build clang), but I’m still having problems getting the library to work as a whole.