support for cabal/stack scripts

[georgefst]

Certain upcoming features (repl, runghc) are likely to make cabal scripts a much more attractive option.

I, for one, would like to switch all of my turtle scripts to use them, rather than (as at present) having them all in a single cabal project. But I wouldn't want to lose the IDE support...

Would there be any major difficulty in supporting these? Is this actually more of a question for hie-bios?

[fendor]

Supporting cabal script is a matter of implementing the issue: haskell/cabal#6149

That is why stack scripts are already supported via hie-bios.

I started to implement it, but there are a few roadbumps that makes it not as easy as hoped.

[jneira]

As commented in https://github.com/haskell/ghcide/issues/162 and here, there is a workaround to make stack scripts work:

Stack scripts work in a "hacky" way.
You have to add an explicit hie.yaml file with the contents:

cradle:
  stack:
    component: "File.hs" # your local stack script

Works fine for loading and modifying the stack script.
However, if you modify the script section, these changes wont be detected, e.g. you have to restart ghcide/hls.

The reason this works is that you can do stack repl File.hs and the session is loaded correctly.

by @fendor

[jneira]

Related issue in hi-bios: haskell/hie-bios#217

[fendor]

Afaik, stack repl File.hs ceased to work for stack scripts, therefore it does not work anymore with HLS :(
I dont remember in which stack version it used to work (before 1.9.3?) and I cant find any related stack issues for it

[georgefst]

FWIW, I have been making a lot of use of Cabal scripts, using cabal install --package-env . --lib [...]. It's not ideal, but I can live with it for now. Doesn't even require a cradle (EDIT: an explicit hie.yaml - you know what I mean). I don't think this worked when I opened the issue, but I can't remember why.

If it weren't for haskell/cabal#6999 things would actually be rather nice.

[jneira]

@Ailrun this one would be related with #692? (so it would be included for gsoc as well in the same pack)