haskell/haskell-language-server

haskell-language-server-9.10.3: internal error: ARR_WORDS object (0x42c022fc68) entered!

Closed this issue · 3 comments

carbolymer commented

Your environment

This happens on both my local Archlinux machine and nix environment in our CI

Which OS do you use? ArchLinux / NixOS
Which version of GHC do you use and how did you install it? 9.10.3 from ghcup / 9.10.2 from haskell.nix
How is your project built (alternative: link to the project)? pure cabal / haskell.nix

Which LSP client (editor/plugin) do you use?
neovim + haskell-tools.nvim / standalone HLS
Which version of HLS do you use and how did you install it?

  • AUR haskell-language-server version: 2.12.0.0 (GHC: 9.10.3) (PATH: /usr/lib/haskell-language-server-2.12.0.0/bin/haskell-language-server-wrapper) from /
  • haskell.nix: 2.12.0.0 (GHC: 9.10.2) (PATH: /nix/store/8yr49yqkw2akbsji2qvss55pfrq7d87q-haskell-language-server-exe-haskell-language-server-2.12.0.0/bin/haskell-language-server)

Have you configured HLS in any way (especially: a hie.yaml file)?

cradle:
  cabal:

Steps to reproduce

Non-nix

Open editor with haskell.nix in the repo https://github.com/IntersectMBO/cardano-api

Nix

We have a CI action which runs the HLS and verifies that it still works in our codebase:
.github/workflows/hls.yml updated in this PR: https://github.com/IntersectMBO/cardano-api/pull/963/files

But it results in a failure: https://github.com/IntersectMBO/cardano-api/actions/runs/19104073385/job/54583074489?pr=963#step:9:2436

 2025-11-05T14:24:08.556365Z | Info | hlint: updateFileDiagnostics published different from new diagnostics - file diagnostics: File:    
  /home/runner/work/cardano-api/cardano-api/cardano-api/src/Cardano/Api/LedgerState/Internal/LedgerEvent.hs
Hidden:   no
Range:    118:7-119:39
Source:   hlint
Severity: DiagnosticSeverity_Information
Code:     refact:Functor law
Message: 
  Functor law
  Found:
  fmap (Map.mapKeys StakePoolKeyHash)
  . (fmap . fmap) Ledger.fromCompact
  Why not:
  fmap (Map.mapKeys StakePoolKeyHash . fmap Ledger.fromCompact)
haskell-language-server: internal error: ARR_WORDS object (0x4269419690) entered!
    (GHC version 9.10.2 for x86_64_unknown_linux)
    Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug

Expected behaviour

HLS does not crash with GHC error.

Actual behaviour

HLS does not crash

Debug information

carbolymer commented

I suppose I should report this at GHC bug tracker but I figured out I'd let you know first.

carbolymer commented

Looks like there's an issue on GHC bug tracker already: https://gitlab.haskell.org/ghc/ghc/-/issues/26033

carbolymer commented

There exists a bug report for that already. I'm closing this as a duplicate: #4674

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