GHC 9.6.6 fails with lookupIdSubst panic

README.md

GHC 9.6.6 fails with lookupIdSubst panic

https://gitlab.haskell.org/ghc/ghc/-/issues/25064

When I tried to compile the Bug.hs (which actually contains type errors) using GHC 9.6.6 and Stackage LTS 22.28, GHC panics with lookupIdSubst:

% stack build
bug> configure (lib)
Configuring bug-0.1.0.0...
bug> build (lib) with ghc-9.6.6
Preprocessing library for bug-0.1.0.0..
Building library for bug-0.1.0.0..
[1 of 1] Compiling Bug

<no location info>: error:
    panic! (the 'impossible' happened)
  GHC version 9.6.6:
	lookupIdSubst
  $dPrimMonad_a1Ft
  InScope {m_a1pT a_a1pU $dPrimMonad_a1pV table getNext nodeSymbol
           newRule g h}
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/GHC/Utils/Panic.hs:189:37 in ghc:GHC.Utils.Panic
        pprPanic, called at compiler/GHC/Core/Subst.hs:197:17 in ghc:GHC.Core.Subst
  CallStack (from HasCallStack):
    panic, called at compiler/GHC/Utils/Error.hs:454:29 in ghc:GHC.Utils.Error


Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug


Error: [S-7282]
       Stack failed to execute the build plan.
       
       While executing the build plan, Stack encountered the error:
       
       [S-7011]
       While building package bug-0.1.0.0 (scroll up to its section to see the error) using:
       /Users/sakai/.stack/setup-exe-cache/aarch64-osx/Cabal-simple_HwdwpEmb_3.10.3.0_ghc-9.6.6 --verbose=1 --builddir=.stack-work/dist/aarch64-osx/ghc-9.6.6 build lib:bug --ghc-options ""
       Process exited with code: ExitFailure 1 

bug.cabal

cabal-version: 1.12

name:           bug
version:        0.1.0.0
build-type:     Simple

library
  exposed-modules:
      Bug
  hs-source-dirs:
      ./
  build-depends:
      base >=4.7 && <5
    , hashtables
    , primitive
  default-language: Haskell2010

Bug.hs

module Bug where

import Control.Monad.Primitive
import qualified Data.HashTable.ST.Basic as H

data Symbol a = Symbol

data Node s a = Node

data Rule s a = Rule (Node s a)

data S s a
  = S
  { table :: H.HashTable s (Symbol a, Symbol a) (Node s a)
  }

getNext :: PrimMonad m => Node (PrimState m) a -> m (Node (PrimState m) a)
getNext = undefined

nodeSymbol :: Node s a -> Symbol a
nodeSymbol = undefined

newRule :: PrimMonad m => S (PrimState m) a -> (Symbol a, Symbol a) -> m (Rule (PrimState m) a)
newRule = undefined

f :: PrimMonad m => S (PrimState m) a -> Node (PrimState m) a -> m ()
f s n1 = do
  n2 <- getNext n1
  let x = (nodeSymbol n1, nodeSymbol n2)
  ret <- stToPrim $ H.lookup (table s) x
  case ret of
    Nothing -> return ()
    Just n1' -> do
      n2' <- getNext n1'
      ret <- g n1' n2'
      case ret of
        Just _ -> return ()
        Nothing -> do
          rule <- newRule x
          h s n1  rule
          return ()

g :: PrimMonad m => S (PrimState m) a -> Node (PrimState m) a -> Node (PrimState m) a -> m (Maybe (Rule (PrimState m) a))
g = undefined

h :: PrimMonad m => S (PrimState m) a -> Node (PrimState m) a -> Rule (PrimState m) a  -> m ()
h = undefined

Setup.hs

import Distribution.Simple
main = defaultMain

stack.yaml

resolver:
  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/22/28.yaml

packages:
- .