ghc-debug on HeapOverflow

build.sh

#!/bin/bash

rm test.o

ghc -rtsopts -threaded test.hs

# run like the following
# GHC_DEBUG_SOCKET=/tmp/ghc-debug ./test +RTS -M1G

flake.nix

{
  description = "heapoverflow-ghc-debug-test";
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/master";
    flake-utils.url = "github:numtide/flake-utils";
  };
  outputs = {self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let pkgs = import nixpkgs { inherit system; };
          hspkgs = pkgs.haskell.packages.ghc962.override (old: {
            overrides = hself: hsuper: {
              ghc-debug-stub = pkgs.haskell.lib.doJailbreak (hself.callHackage "ghc-debug-stub" "0.4.0.0" {});
              ghc-debug-convention = hself.callHackage "ghc-debug-convention" "0.4.0.0" {};
            };
          });
          hsenv = hspkgs.ghcWithPackages (p: [
            p.ghc-debug-stub
            p.cabal-install
          ]);
      in {
        devShells.default =
          pkgs.mkShell {
            buildInputs = [hsenv];
          };
        }
    );
}

test.hs

{-# LANGUAGE NumericUnderscores #-}

module Main where

import Control.Concurrent
  ( forkIO,
    threadDelay,
  )
import Control.Exception
  ( AsyncException (HeapOverflow),
    catch,
  )
import Data.List (foldl)
import GHC.Debug.Stub
  ( pause,
    withGhcDebug,
  )

main' :: IO ()
main' = do
  forkIO $ do
    let x = foldl (+) 0 [0..1_000_000_000]
    print x
  threadDelay 10_000_000

main :: IO ()
main =
  withGhcDebug $ 
    catch main' $ \(e :: AsyncException) ->
      case e of
        HeapOverflow -> do
          print "yay! HeapOverflow!"
          print "i am pausing"
          pause
        _ -> pure ()