- r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
- i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
- i1 `le_fam_inst` i2 = ifFamInstTyConOcc i1 <= ifFamInstTyConOcc i2
+ r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
+ i1 `le_inst` i2 = ifDFun i1 `le_occ` ifDFun i2
+ i1 `le_fam_inst` i2 = ifFamInstTcName i1 `le_occ` ifFamInstTcName i2
+
+ le_occ :: Name -> Name -> Bool
+ -- Compare lexicographically by OccName, *not* by unique, because
+ -- the latter is not stable across compilations
+ le_occ n1 n2 = nameOccName n1 <= nameOccName n2