Sure, no problem and nothing changes, the bug is still there.

For that GHC version you need the `bug73500.cabal` in the newly attached file (with dropped version constraints). It also includes the new `lsp-ghc92.log` transcript of `eglot` events including the diagnostics and `screenshot/emacs-ghc92.png` showing the fringe exclamation mark, but no underlining.

You must have the package `cabal-instal` providing the executable `cabal`. You can test that it works by running `cabal build` in the directory containing the cabal file.


On 29/09/2024 19:20, João Távora wrote:
On Sun, Sep 29, 2024, 18:00 Federico Beffa <federico.beffa@fbengineering.ch> wrote:
On 28/09/2024 23:18, João Távora wrote:
On Sat, Sep 28, 2024 at 4:23 PM Federico Beffa 
... Anyway, I couldn't reproduce your problem simply because the Main.hs
program you provided does not seem to produce any diagnostics, according
the haskell-language-server I installed in my system, which identifies
itself as

haskell-language-server version: 1.9.1.0 (GHC: 9.2.8) (PATH: /usr/bin/haskell-language-server)
This is not the version I indicated in the `README.md` file: GHC 9.6.5 with the supported haskell-language-server 2.8.0.0 (indicated in the initial bug report).

Well that's the server archlinux has on its repos.

Please use the indicated tool versions.

No I won't do that, sorry. Maybe you'll find someone who has time to install your specific toolkit. But you can try out my recipe and see if you get the one-char underlines I got.

João