Crash compiling HPC with certain unsafe code

Summary

When compiling certain code that uses both unsafeCoerce and reallyUnsafePtrEquality#, the compiler crashes with an incomplete pattern match.

Steps to reproduce

Compile the following module with ghc -fhpc:

{-# LANGUAGE MagicHash #-}

module HPsea where

import GHC.Exts
import Unsafe.Coerce

hetPtrEq :: a -> b -> Bool
hetPtrEq x y = isTrue# (unsafeCoerce (reallyUnsafePtrEquality# :: x -> x -> Int#) x y)

This crashes:

[1 of 1] Compiling HPsea            ( HPsea.hs, HPsea.o ) [Source file changed]

<no location info>: error:
    compiler/GHC/StgToCmm/Prim.hs:(340,32)-(341,74): Non-exhaustive patterns in lambda

I have not, thus far, been able to reproduce the problem without unsafeCoerce or without reallyUnsafePtrEquality#, but I admit I haven't tried terribly hard.

Expected behavior

I expect the code to compile successfully, and definitely not to crash the compiler.

Environment

• GHC version used: 9.8.2

Optional:

• Operating System:
• System Architecture: