Nondeterministic segfault on simple hspec program with GHC 9.0 only

(Originally reported at https://github.com/ekmett/reflection/issues/51.)

The reflection-2.1.6 test suite nondeterministically segfaults on Linux and macOS when compiled with GHC 9.0.1 or 9.0.2. The furthest I've managed to minimize the issue is:

{-# LANGUAGE PackageImports #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Main (main) where

import Control.Exception (ArithException(..), evaluate)
import Numeric.Natural (Natural)
import "hspec" Test.Hspec
import "hspec" Test.Hspec.QuickCheck
import "QuickCheck" Test.QuickCheck (Negative(..), NonNegative(..))

main :: IO ()
main = hspec spec

spec :: Spec
spec =
  describe "A" $ do
    describe "B" $ do
      prop "identity" $
        \(NonNegative (i :: Integer)) -> i `shouldBe` i
      prop "should throw an Underflow exception on negative inputs" $
        \(Negative (i :: Integer)) ->
          evaluate (fromInteger i :: Natural) `shouldThrow` (== Underflow)

With GHC 8.10.7 or 9.2.1, this works as expected:

$ ghc-8.10.7 Bug.hs && ./Bug
Loaded package environment from /home/ryanglscott/Documents/Hacking/Haskell/ci-maintenance/checkout/ekmett/reflection/.ghc.environment.x86_64-linux-8.10.7
[1 of 1] Compiling Main             ( Bug.hs, Bug.o )
Linking Bug ...

A
  B
    identity [✔]
      +++ OK, passed 100 tests.
    should throw an Underflow exception on negative inputs [✔]
      +++ OK, passed 100 tests.

Finished in 0.0009 seconds
2 examples, 0 failures

$ ghc-9.2.1 Bug.hs && ./Bug
Loaded package environment from /home/ryanglscott/Documents/Hacking/Haskell/ci-maintenance/checkout/ekmett/reflection/.ghc.environment.x86_64-linux-9.2.1
[1 of 1] Compiling Main             ( Bug.hs, Bug.o )
Linking Bug ...

A
  B
    identity [✔]
      +++ OK, passed 100 tests.
    should throw an Underflow exception on negative inputs [✔]
      +++ OK, passed 100 tests.

Finished in 0.0013 seconds
2 examples, 0 failures

With GHC 9.0.2, however, this can segfault:

$ ghc-9.0.2 Bug.hs && ./Bug
Loaded package environment from /home/ryanglscott/Documents/Hacking/Haskell/ci-maintenance/checkout/ekmett/reflection/.ghc.environment.x86_64-linux-9.0.2
[1 of 1] Compiling Main             ( Bug.hs, Bug.o )
Linking Bug ...

A
  B
    identity [✔]
      +++ OK, passed 100 tests.
    should throw an Underflow exception on negative inputs [ ]Segmentation fault (core dumped)

This is somewhat nondeterministic. In situations where it doesn't segfault, an incorrect runtime result will be observed:

$ ./Bug

A
  B
    identity [✔]
      +++ OK, passed 100 tests.
    should throw an Underflow exception on negative inputs [✘]

Failures:

  Bug.hs:22:47: 
  1) A.B should throw an Underflow exception on negative inputs
       Falsifiable (after 54 tests and 2 shrinks):
         Negative {getNegative = -1}
       did not get expected exception: ArithException

  To rerun use: --match "/A/B/should throw an Underflow exception on negative inputs/"

Randomized with seed 1065015581

Finished in 0.0028 seconds
2 examples, 1 failure

This example proves remarkably resistant to minimization, as attempting to delete code in various places seemingly makes the bug disappear.