Setting up Haskell development environment for Neovim (2022)

Written 3 years ago

This is mostly for my sake in case I need it again but may help others avoid the pitfalls I faced, so sharing here.

In shell (I’m on Manjaro Linux)

Do NOT install stack, cabal, ghc, ghci, ghcid and what have you separately.

  1. Install ghcup yay -S ghcup-hs-bin, check this link haskell.org/ghcup for other platforms.

  2. Install ghc, stack and cabal using ghcup tui. DO NOT INSTALL HLS YET!

    1. [I]nstall recommended versions. Make sure hls supports that version here.

    2. [S]et them as default. ghc, stack, and cabal should be available on path.

Note: one tick = installed, another tick = default

In neovim

I’m using built-in LSP along with nvim-lsp-installer plugin for convenience. Check this file full setup.

  1. Open a temp.hs file

  2. :LspInstallInfo should show a green hls available

  3. [I]nstall, drink your coffee, close and reopen file.

  4. Profit!

nvim-lspconfig nvim-lsp-installer nvim-cmp

Yes these simple steps took me almost a day of stumbling around. Hopefully, next time it’ll be done in minutes.