The signatures in the specification¹ differ from the signatures of the functions in the source code. The function Fenix_Data_member_restore_from_rank(...) has a typo in its name in the .c file and different signatures in the .c and .h files. Additionally, it seems to be not implemented although described in the documentation.
¹ I'm referring to https://raw.githubusercontent.com/epizon-project/Fenix/master/doc/fenix_spec.pdf and https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/fenix_exa.pdf is there an updated version?