libmumps64-seq-dev 5.3.5-1build1 (riscv64 binary) in ubuntu hirsute

 MUMPS implements a direct solver for large sparse linear systems, with a
 particular focus on symmetric positive definite matrices. It can
 operate on distributed matrices e.g. over a cluster. It has Fortran and
 C interfaces, and can interface with ordering tools such as Scotch.
 .
 This package is built the MUMPS libseq dummy sequential MPI library.
 Unless you know that you specifically need this, then you almost
 certainly want the libmumps64-dev package.
 .
 This package supports 64-bit ordering (-DPORD_INTSIZE64).