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haskell / haskell-ide-engine

The engine for haskell ide-integration. Not an IDE
BSD 3-Clause "New" or "Revised" License
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failing to recognize some modules #1069

Open dc25 opened 5 years ago

dc25 commented 5 years ago

I'm using hie from inside vim and for the most part it seems to be working. However at least one module (Data.Aeson) is not being recognized. Autocomplete does not show this module as an option when I type it in and the editor shows an error saying that the module does not exist: "LSP: Could not find module Data.Aeson. Perhaps you meant Data.Version..."

I know the module is there because I can compile the file just fine.

lorenzo commented 5 years ago

did you add the aeson package to your cabal or package.yaml file?

dc25 commented 5 years ago

No. I'm using nix and don't have either a cabal or package.yaml file. Is hie behavior affected by the contents of these files?

lorenzo commented 5 years ago

Yes, it is. We use ghc-mod under the hood (as far as my understanding goes) it uses those files to understand where things are installed and what packages are available. I've never used nix, though, but my experience with using hie and a global GHC installation is that I need a cabal file at least to help HIE understand what packages are available.

dc25 commented 5 years ago

Thank you. I used cabal init to create a cabal file and built my test program using cabal build to verify the integrity of the cabal file. Now when I edit the file, I get no response at all from vim-lsp/hie . I can, however, use ps -ef to see that hie-wrapper and hie-8.6 both started when I started nvim to edit main.hs . If I then delete the cabal file and restart nvim, I start to see feedback from hie as I edit. What is going on here?

After seeing your previous comment, I looked back over the hie documention and didn't see anything that suggested that a cabal file is required. The first bullet point under Features says "Supports plain GHC projects, cabal projects(sandboxed and non sandboxed) and stack projects" . If a cabal file is required to help HIE understand what packages are available, then "Supports plain GHC projects" should probably be removed from the bullet point.

Is this the best place to report this kind of problem? I would really like to get hie working and I would also like to help improve the package by reporting any problems that I run into and ( if they are actually bugs and they get fixed ) verifying the bug fixes. I already opened a related question on stackoverflow and mentioned it on reddit.com/r/haskell but, so far, have gotten no response on either.