Another finding:
/usr/bin/freesolid-config (Part of *-devel) contains hard-coded paths to
%{_libdir}.
This prevents parallel installation of *-devel.i386 and *-devel.x86_64 and
means this package is not multilib-ready.
A common work-around to this kind of issues is to rewrite such *-config scripts
as wrappers to pkg-config.
A brute-force, last resort would be not to ship the *-config script.