The clpq and clpr libraries are‘orphaned’, i.e., they currently have no maintainer.
?- {X+Y>=1}. {Y=1-X+_G2160, _G2160>=0}. ?-
Nonetheless, for linear constraints this kind of answer means unconditional satisfiability.
?- {X=1},dump([X],[Y],L). ERROR: Unhandled exception: Unknown message: instantiation_error(dump([1],[_G11],_G6),1) ?-