Comment (by Cheng-Hsin Cheng):

Sorry, I am still not understanding how this can be resolved. The ADIOS2 library was configured without Fortran support by default, and I don't understand how it would affect the compilation for the C files. How should I configure my build?

--
Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2923/adios2-compilation-fails-due-to-unknown