Embarrassingly I had too many tabs open and realised I replied to the wrong thread…it won’t let me repost the same and I can’t delete the old one, but can see here: Neovim: nvim-lsp + elixir - #17 by te_chris
Basically, I’m using nvim and the NVChad config. Have installed the elixirls package with mason and LspInfo says it’s being used. I’m not getting any completions though. Debug suggestions welcome!
Just a note as it might help someone. Had nvim + elixirls + treesitter nicely working, except syntax highlighting for ~H sigils. Bashed my head against the wall to figure out why, reinstalled & updated all dependencies and tried everything I found online, almost gave up, then decided to update neovim itself (from 0.8.2 to 0.9.2). And boom, it works!
tl;dr: make sure neovim is up to date 
Another tip: As of Aug 2023, packer.nvim is unmaintained. I migrated to lazy.nvim - smooth transition. For me lazy runs faster and is simpler to setup.
I would suggest not just using lazy package manager but the LazyVim distro.
LazyVim is by the far the cleanest and well structured nvim distro I have used. I have used a number of distros including bootstrapping nvim from scratch. LazyNvim is not intrusive, its transparent and very easy to get started and customise however you want.
One of the great features of LazyNvim that it has working Elixir language support out of the box.
I use asdf to ensure I have a very recent stable version of nvim and recommend asdf as the way to go for installing and managing versions of Erlang/OTP, node etc too.
The Elixir plugin is described here, along with all the plugin defaults it enables:
One you have followed the easy peasy LazyVim installation, just add a single elixir plugin “lazyvim.plugins.extras.lang.elixir” to lua/config/lazy.lua and you’re cooking with gas:
require("lazy").setup({
spec = {
{ "LazyVim/LazyVim", import = "lazyvim.plugins" },
{ import = "lazyvim.plugins.extras.lang.elixir" },
{ import = "plugins" },
},
})
Neovim ecosystem is evolving fast. Actually I’ve switched to lazy.nvim plugin manager since the discontinued development of packer.nvim. I’ll update the guide when I’ve got time.
3 months later: I am gonna call you out on that. I have been using GitHub - jdx/mise: dev tools, env vars, task runner · GitHub for a few months now and I like it more. It’s absolutely instantaneous at whatever you give it to do (minus the networked operations). And I’ve observed asdf being slow in a number of occasions which always baffled me because really, what does that thing have to do? It isn’t much, yet it still manages to lag. (And the rtx author claims that asdf also adds overhead via its shims, and says that rtx does not.)
rtx fixed that for me. It’s completely invisible and is uber fast, and is compatible with all asdf plugins. It’s a drop-in replacement, with only 1-2 gotchas on how to set global versions of tools (slightly different than asdf but it can also work just fine with .tool-versions files as well).
I haven’t tried rtx yet but I have been meaning to give it a go, but asdf is not slowing me down enough to bother right now.
Works like charm. Thanks for this little tutorial.
Im running FreeBSD, so to make elixir-ls to run and not quit on me at the startup, I had to change the #!/bin/sh to use #!/usr/local/bin/bash as ‘<<<’-operator isnt supported by sh.
