Version 2.3.5 is available upstream. Please consider updating! It seems that version 2.3.5 is available upstream, while the latest version in the Gentoo tree is 2.0.3. You think this warning is false? Read more about it here.
suitesparseconfig-7.0.0 fails to build with multilib enabled because of dependencies that cannot be satisfied. All the other packages require it. Bug #908851.
KLU is a sparse LU factorization algorithm well-suited for use in
circuit simulation. It is also part of the University
of Florida sparse matrix suite.