InterfaceMode _ -> returnM () ; -- Don't warn of unused tyvars in interface files
-- unless DEBUG is on, in which case it is slightly
-- informative. They can arise from mkRhsTyLam,
InterfaceMode _ -> returnM () ; -- Don't warn of unused tyvars in interface files
-- unless DEBUG is on, in which case it is slightly
-- informative. They can arise from mkRhsTyLam,