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)
?-