@samueljohn I ended up pushing a better version of this update because it worked on all the different option configurations I could test (a lot of building). I took a deep breath before hand, though. But, one thing has actually stood out to me since I first wrote this formula and it just occurred to me. 

This line above (from the first version) assumes the gfortran library must be linked. However, the user is technically allowed to change the fortran compiler with `FC=ifort` as an example, so how should fortran linker flags be passed? Is it standard to use `FCFLAGS` or `FFLAGS`? Also, if `FC` is not gfortran, I guess we should not link to this library. What is the best way to do this? Since no one is complaining, I suspect not a lot of users are installing custom fortran compilers for lammps, but it is certainly possible.