Test Trac #7524

testsuite/tests/polykinds/T7524.hs

+{-# LANGUAGE TypeFamilies, PolyKinds #-}
+module T7524 where
+
+type family F (a :: k1) (b :: k2)
+type instance F a a = Int
+type instance F a b = Bool

testsuite/tests/polykinds/T7524.stderr

+
+T7524.hs:5:15:
+    Conflicting family instance declarations:
+      F k k a a -- Defined at T7524.hs:5:15
+      F k k1 a b -- Defined at T7524.hs:6:15

testsuite/tests/polykinds/all.T

@@ -83,3 +83,4 @@ test('T7404', normal, compile_fail,[''])
 test('T7502', normal, compile,[''])
 test('T7488', normal, compile,[''])
 test('T7594', normal, compile_fail,[''])
+test('T7524', normal, compile_fail,[''])