Version 1.8.9 is available upstream. Please consider updating! It seems that version 1.8.9 is available upstream, while the latest version in the Gentoo tree is 1.8.8. You think this warning is false? Read more about it here.
BONMIN (Basic Open-source Nonlinear Mixed INteger programming) is an
open-source code for solving general MINLP (Mixed Integer NonLinear
Programming) problems.