Simon Hengel

> Yes, I tried it and it gives me an error when running `doctest`: > > ``` > [nix-shell:~/code/dump-decls]$ doctest -isrc dump-decls-lib/src/ > > dump-decls-lib/src/Compat/Aeson.hs:11:5: error: > error: function-like macro...

What I'm saying is, if you can, upgrade to a more recent version of GHC first (at least 9.8.*). If you don't do that, you have to be prepared to...

For completeness: #### With GHC 9.8+ - Whenever the path to `ghc` in the nix store changes, but the `Project Unit Id` (look at `ghc --info`) does does not change...

Would `hie-bios` benefit from this as well? @fendor

> Note that for test stanzas, the code-generators field (https://cabal.readthedocs.io/en/stable/file-format-changelog.html#cabal-version-3-8) will produce all options that would be sent to ghc for a build, and allow invoking a custom executable (via...

> I find the idea of with-repl quite clever but if the goal is to find what arguments to invoke ghc with... cannot we just do that instead? That would...

1. Since `cabal-install-3.12.*` you can use `--repl-multi-file` to capture the options that `cabal repl` would pass to GHC. This is what I currently use for [`cabal doctest`](https://github.com/sol/doctest/issues/428). 2. This is...

Another issue with the `--repl-multi-file` workaround is that it does not bring `build-tools` into scope.

I would also hope that this will solve the issue with build tools not being in scope for HLS. This is currently a regular annoyance I run into.

@mpickering did you see my comment at https://github.com/haskell/cabal/issues/10915#issuecomment-3037319966. The bottom line is that `doctest` users use `--with-compiler`. I can change the documentation, and I can change `cabal-doctest`. But this won't...