How to make libtool to use the external linker to link only one shared library in a large project?

[Yuri]

The fftw3 project needs to link one of many libraries (libfftw3_mpi.so) 
with the externally supplied linked (mpicc executable). The rest of the 
project needs to be linked in a default way.

Could you please advise how to do this?

Neither me nor the project's maintainers know how to do this, and this 
library is built with missing MPI library linkage, and therefore with 
dangling symbols.


The conversation: https://github.com/FFTW/fftw3/issues/169


Thank you,

Yuri