testsuite/tests/rename/should_fail/T18021.stderr

 
 T18021.hs:12:3: error: [GHC-53634]
-    The RHS of an associated type declaration mentions out-of-scope variable ‘a’
-      All such variables must be bound on the LHS
+    Out of scope type variable ‘a’ in the RHS of a family instance.
+      All such variables must be bound on the LHS.
 
 T18021.hs:17:3: error: [GHC-53634]
-    The RHS of an associated type declaration mentions out-of-scope variable ‘a’
-      All such variables must be bound on the LHS
+    Out of scope type variable ‘a’ in the RHS of a family instance.
+      All such variables must be bound on the LHS.

testsuite/tests/rename/should_fail/T18240a.stderr

@@ -28,16 +28,16 @@ T18240a.hs:23:19: error: [GHC-71492]
     • Instance head cannot contain nested ‘forall’s or contexts
     • In an instance declaration
 
-T18240a.hs:28:10: error: [GHC-12222]
-    • Illegal head of an instance declaration: ‘42’
-        Instance heads must be of the form
-          C ty_1 ... ty_n
-        where ‘C’ is a class
+T18240a.hs:28:10: error: [GHC-53946]
+    • Illegal head of an instance declaration: ‘42’.
+      Instance heads must be of the form
+        C ty_1 ... ty_n
+      where ‘C’ is a class.
     • In an instance declaration
 
-T18240a.hs:29:10: error: [GHC-12222]
-    • Illegal head of an instance declaration: ‘Int -> Int’
-        Instance heads must be of the form
-          C ty_1 ... ty_n
-        where ‘C’ is a class
+T18240a.hs:29:10: error: [GHC-53946]
+    • Illegal head of an instance declaration: ‘Int -> Int’.
+      Instance heads must be of the form
+        C ty_1 ... ty_n
+      where ‘C’ is a class.
     • In an instance declaration

testsuite/tests/rename/should_fail/T5513.stderr

 
-T5513.hs:4:19: error: [GHC-56538]
-    • Instance head is not headed by a class: lowercase_name a
+T5513.hs:4:19: error: [GHC-53946]
+    • Illegal head of an instance declaration: ‘lowercase_name a’.
+      Instance heads must be of the form
+        C ty_1 ... ty_n
+      where ‘C’ is a class.
     • In the stand-alone deriving instance for ‘lowercase_name a’

testsuite/tests/roles/should_fail/T23252.stderr

-T23252.hs:11:1: error:
+
+T23252.hs:11:1: error: [GHC-87279]
     • The kind of ‘T2’ is ill-scoped
         Inferred kind: T2 :: forall (d :: k).
                              forall k (c :: k) (a :: Proxy c) (b :: Proxy d) ->

testsuite/tests/simplCore/should_compile/T23630.hs

+module T23630 where
+
+data HOLType = UTypeIn !HOLType deriving Eq
+
+tyVars :: HOLType -> [HOLType]
+tyVars (UTypeIn tv) = [undefined]
+
+union :: Eq a => [a] -> [a] -> [a]
+union l1 l2 = foldr insert l2 l1
+
+insert :: Eq a => a -> [a] -> [a]
+insert x l
+    | x `elem` l = l
+    | otherwise = x : l
+
+catTyVars :: [HOLType] -> [HOLType]
+catTyVars = foldr (union . tyVars) []

testsuite/tests/simplCore/should_compile/all.T

@@ -472,6 +472,7 @@ test('T22715_2', normal, multimod_compile, ['T22715_2', '-v0 -O -fspecialise-agg
 test('T22802', normal, compile, ['-O'])
 test('T15205', normal, compile, ['-O -ddump-simpl -dno-typeable-binds -dsuppress-uniques'])
 test('T22761', normal, multimod_compile, ['T22761', '-O2 -v0'])
+test('T23630', normal, compile, ['-O'])
 test('T23012', normal, compile, ['-O'])
 
 test('RewriteHigherOrderPatterns', normal, compile, ['-O -ddump-rule-rewrites -dsuppress-all -dsuppress-uniques'])

testsuite/tests/typecheck/should_compile/T23413.hs

+module T23413 where
+
+f :: (Int ~ Bool) => Int -> Bool
+f x = f x
+
+g1 :: (Int ~ Bool) => Int -> Bool
+g1 x = f x
+
+g2 :: (Bool ~ Int) => Int -> Bool
+g2 x = f x
+
+h :: (Int ~ Bool) => Int -> Bool
+h x = x

testsuite/tests/typecheck/should_compile/all.T

@@ -888,3 +888,4 @@ test('T23514c', normal, compile, [''])
 test('T22537', normal, compile, [''])
 test('T18986a', normal, compile, [''])
 test('T18986b', normal, compile, [''])
+test('T23413', normal, compile, [''])

testsuite/tests/typecheck/should_fail/AssocTyDef02.stderr

 
-AssocTyDef02.hs:7:5: error:
+AssocTyDef02.hs:7:5: error: [GHC-41522]
     • Illegal argument ‘[b]’ in:
         ‘type Typ [b] = ...’
-        The arguments to ‘Typ’ must all be distinct type variables
+        The arguments to ‘Typ’ must all be distinct type variables.
     • In the default type instance declaration for ‘Typ’
       In the class declaration for ‘Cls’

testsuite/tests/typecheck/should_fail/AssocTyDef03.stderr

 
-AssocTyDef03.hs:6:5: [GHC-52347]
-    Wrong category of family instance; declaration was for a data family
-    In the default type instance declaration for ‘Typ’
-    In the class declaration for ‘Cls’
+AssocTyDef03.hs:6:5: error: [GHC-52347]
+    • Wrong category of family instance; declaration was for a data family.
+    • In the default type instance declaration for ‘Typ’
+      In the class declaration for ‘Cls’

testsuite/tests/typecheck/should_fail/AssocTyDef05.stderr

 
 AssocTyDef05.hs:6:5: error: [GHC-12985]
-    • Number of parameters must match family declaration; expected 1
+    • Number of parameters must match family declaration; expected 1.
     • In the default type instance declaration for ‘Typ’
       In the class declaration for ‘Cls’

testsuite/tests/typecheck/should_fail/AssocTyDef06.stderr

 
-AssocTyDef06.hs:6:5: [GHC-12985]
-    Number of parameters must match family declaration; expected 1
-    In the default type instance declaration for ‘Typ’
-    In the class declaration for ‘Cls’
+AssocTyDef06.hs:6:5: error: [GHC-12985]
+    • Number of parameters must match family declaration; expected 1.
+    • In the default type instance declaration for ‘Typ’
+      In the class declaration for ‘Cls’

testsuite/tests/typecheck/should_fail/ContextStack1.stderr

 
-ContextStack1.hs:10:5:
-    Reduction stack overflow; size = 11
-    When simplifying the following type: Cls [[[[[[[[[[()]]]]]]]]]]
-    Use -freduction-depth=0 to disable this check
-    (any upper bound you could choose might fail unpredictably with
-     minor updates to GHC, so disabling the check is recommended if
-     you're sure that type checking should terminate)
-    In the expression: meth
-    In an equation for ‘t’: t = meth
+ContextStack1.hs:10:5: error: [GHC-40404]
+    • Reduction stack overflow; size = 11
+      When simplifying the following type: Cls [[[[[[[[[[()]]]]]]]]]]
+    • In the expression: meth
+      In an equation for ‘t’: t = meth
+    Suggested fix:
+      Use -freduction-depth=0 to disable this check
+      (any upper bound you could choose might fail unpredictably with
+       minor updates to GHC, so disabling the check is recommended if
+       you're sure that type checking should terminate)

testsuite/tests/typecheck/should_fail/MultiAssocDefaults.stderr

-MultiAssocDefaults.hs:7:1: [GHC-59128]
-     More than one default declaration for A
-     In the class declaration for ‘C’
+
+MultiAssocDefaults.hs:7:1: error: [GHC-59128]
+    • More than one default declaration for ‘A’
+    • In the class declaration for ‘C’

testsuite/tests/typecheck/should_fail/T15515.stderr

 
-T15515.hs:17:10: error:
+T15515.hs:17:10: error: [GHC-73138]
     • Illegal type synonym family application ‘F’ in instance:
         C @{F -> *} D
     • In the instance declaration for ‘C (D :: F -> Type)’

testsuite/tests/typecheck/should_fail/T22570.stderr

 
 T22570.hs:11:10: error: [GHC-53946]
-    • Illegal instance for a type synonym
-      A class instance must be for a class
+    • Illegal instance for type synonym ‘SomeClassUnit’.
+      Instance heads must be of the form
+        C ty_1 ... ty_n
+      where ‘C’ is a class.
     • In the instance declaration for ‘SomeClassUnit’
 
 T22570.hs:15:10: error: [GHC-53946]
-    • Illegal instance for a type synonym
-      A class instance must be for a class
+    • Illegal instance for type synonym ‘SomeClassSyn’.
+      Instance heads must be of the form
+        C ty_1 ... ty_n
+      where ‘C’ is a class.
     • In the instance declaration for ‘SomeClassSyn ()’

testsuite/tests/typecheck/should_fail/T22924b.stderr

 
-T22924b.hs:10:5: error:
+T22924b.hs:10:5: error: [GHC-40404]
     • Reduction stack overflow; size = 201
       When simplifying the following type: S
+    • In the expression: coerce
+      In an equation for ‘f’: f = coerce
+    Suggested fix:
       Use -freduction-depth=0 to disable this check
       (any upper bound you could choose might fail unpredictably with
        minor updates to GHC, so disabling the check is recommended if
        you're sure that type checking should terminate)
-    • In the expression: coerce
-      In an equation for ‘f’: f = coerce

testsuite/tests/typecheck/should_fail/TcCoercibleFail.stderr

@@ -48,16 +48,17 @@ TcCoercibleFail.hs:30:9: error: [GHC-18872]
     • In the expression: coerce :: (VoidBad ()) -> ()
       In an equation for ‘foo5'’: foo5' = coerce :: (VoidBad ()) -> ()
 
-TcCoercibleFail.hs:35:8: error:
+TcCoercibleFail.hs:35:8: error: [GHC-40404]
     • Reduction stack overflow; size = 201
       When simplifying the following type: Fix (Either Age)
+    • In the expression: coerce :: Fix (Either Int) -> Fix (Either Age)
+      In an equation for ‘foo6’:
+          foo6 = coerce :: Fix (Either Int) -> Fix (Either Age)
+    Suggested fix:
       Use -freduction-depth=0 to disable this check
       (any upper bound you could choose might fail unpredictably with
        minor updates to GHC, so disabling the check is recommended if
        you're sure that type checking should terminate)
-    • In the expression: coerce :: Fix (Either Int) -> Fix (Either Age)
-      In an equation for ‘foo6’:
-          foo6 = coerce :: Fix (Either Int) -> Fix (Either Age)
 
 TcCoercibleFail.hs:36:8: error: [GHC-18872]
     • Couldn't match representation of type ‘Either