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Another runtime-rep crash
This program gets a Lint error: ``` {-# LANGUAGE GHC2024, TypeFamilies #-} module Foo where import Data.Kind import GHC.Exts type family F a :: RuntimeRep type instance F Int = LiftedRep g :: forall (r::RuntimeRep). (forall (a :: TYPE r). a -> forall b. b -> b) -> Int g = g foo = g @(F Int) (\x y -> y) ``` Here's the error: ``` *** Core Lint errors : in result of Desugar (before optimization) *** Foo.hs:15:19: warning: From-type of Cast differs from type of enclosed expression From-type: a_aBO Type of enclosed expression: (a_aBO |> (TYPE D:R:FInt)_N) Actual enclosed expression: ds_DCE Coercion used in cast: GRefl representational a_aBO (TYPE D:R:FInt)_N In the RHS of foo :: Int In the RHS of foo_aBW :: Int In the body of lambda with binder a_aBO :: TYPE (F Int) In the body of lambda with binder ds_DCE :: (a_aBO |> (TYPE D:R:FInt)_N) In the body of lambda with binder b_aBS :: * Substitution: <InScope = {a_aBO b_aBS} IdSubst = [] TvSubst = [] CvSubst = []> *** Offending Program *** Rec { g :: forall (r :: RuntimeRep). (forall (a :: TYPE r). a -> forall b. b -> b) -> Int [LclIdX] g = \ (@(r_aBE :: RuntimeRep)) -> (g @r_aBE) `cast` (Sub (forall (a ::~ <TYPE r_aBE>_N). <a -> forall b. b -> b>_N) ->_R <Int>_R :: ((forall (a :: TYPE r_aBE). a -> forall b. b -> b) -> Int) ~R# ((forall (a :: TYPE r_aBE). a -> forall b. b -> b) -> Int)) foo :: Int [LclIdX] foo = letrec { foo_aBW :: Int [LclId] foo_aBW = g @(F Int) (\ (@(a_aBO :: TYPE (F Int))) (ds_DCE :: (a_aBO |> (TYPE D:R:FInt)_N)) (@b_aBS) -> (\ (x_axq :: (a_aBO |> (TYPE D:R:FInt)_N)) (y_axr :: b_aBS) -> y_axr) (ds_DCE `cast` (GRefl representational a_aBO (TYPE D:R:FInt)_N :: a_aBO ~R# (a_aBO |> (TYPE D:R:FInt)_N)))); } in foo_aBW end Rec } ```
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