I’m the primary developer of yaFyaml - and only incidentally stumbled into this thread just now.
I recently released yaFyaml v1.0 which changes some of the interfaces. I’d be happy to help anyone that is having difficulty with installation - it does indeed depend on 2 other packages: gFTL and gFTL-shared. gFTL is a utility that generates templates for software containers with similar interfaces to C++ STL containers. gFTL-shared is a library that instantiates those containers for common cases of intrinsic types. And gFTL-shared includes gFTL as a submodule, so you really only need to install it - installs in a canonical CMake manner.
Happy to help out anyone interested. Contact me on GitHub or email: Thomas.L.Clune@nasa.gov