Error message prints the same text for different types

Summary

With -fno-print-explicit-runtime-reps GHC in error messages prints * even if difference in runtime rep matters to understand why types are different.

Steps to reproduce

module T where

import GHC.Types

type F :: forall r. Type -> TYPE r -> Type
data F a b


type B :: (forall r. TYPE r -> Type) -> Type
data B a = MkB
  deriving Show

b :: B (F Int) 
b = MkB

On this code GHC will output

    • Expected kind ‘* -> *’, but ‘F Int’ has kind ‘* -> *’
    • In the first argument of ‘B’, namely ‘(F Int)’
      In the type signature: b :: B (F Int)
   |
13 | b :: B (F Int)
   |         ^^^^^

Expected * -> *, actual - * -> *, thank you, GHC!

Expected behavior

With -fprint-explicit-runtime-reps error message becomes informative:

    • Expected kind ‘forall (r :: RuntimeRep). TYPE r -> *’,
        but ‘F Int’ has kind ‘TYPE r0 -> *’
...

Environment

• GHC version used: All versions from 9.2 to HEAD show the same behavior, I did not test it on earlier ones.