lsp-nix completions dont work

[Celibistrial]

Thank you for the bug report

• I am using the latest version of lsp-mode related packages.
• I checked FAQ and Troubleshooting sections
• You may also try reproduce the issue using clean environment using the following command: M-x lsp-start-plain

Bug description

No completions when using nil language sever in emacs but works in other code editors (tested in neovim and VScode)
Same issue reported here oxalica/nil#117

Steps to reproduce

Open .nix file and M-x lsp!

Expected behavior

Pressing space+tab should give context appropriate completions but instead gives generic completions / no completions at all

Which Language Server did you use?

lsp-nix

OS

Linux

Error callstack

No response

Anything else?

No response

[psibi]

Pressing space+tab should give context appropriate completions but instead gives generic completions / no completions at all

Can you give a small reproducible example of a nix file that works with other editors too ?

[Celibistrial]

vscode

emacs

example code

{
  inputs = {
    nixpkgs.url = "github:nixOS/nixpkgs/release-23.05";
    utils.url = "github:numtide/flake-utils";
  };
  outputs = {
    nixpkgs,
    utils,
    ...
  }:
    utils.lib.eachSystem ["i686-linux" "x86_64-linux"]
    (system: let
      pkgs = nixpkgs.legacyPackages.${system};
    in rec {
      packages = {
        nbfc = pkgs.stdenv.mkDerivation {
          name = "nbfc-linux";
          version = "0.1.15";

          src = nixpkgs.lib.cleanSource ./.;

          buildFlags = ["PREFIX=$(out)" "confdir=/etc"];
          installFlags = ["PREFIX=$(out)" "confdir=$(out)/etc"];
          installTargets = ["install-core" "install-configs" "install-docs" "install-completion"];
        };
        default = packages.nbfc;
      };
    });
}

[psibi]

@Celibistrial Thanks, that helps. I tried reproducing it in my emacs, but unfortunately couldn't:

I'm using company-mode for the completions.

[Celibistrial]

Hmm , in that case its probably a doom emacs specific issue.

Whats weird is it does seem to give completions but only when i type in the first letter

Relevant parts of my personal config

(after! lsp-ui
  (setq lsp-ui-sideline-show-code-actions   nil)
  (setq lsp-headerline-breadcrumb-enable t)
  (setq lsp-enable-symbol-highlighting t)
  (setq lsp-signature-auto-activate t)

  (setq lsp-headerline-breadcrumb-enable t)
  (setq lsp-ui-sideline-enable t)
  (setq lsp-ui-sideline-enable t)
  (setq lsp-modeline-code-actions-enable t)
  (setq lsp-ui-sideline-enable t)
  (setq lsp-eldoc-enable-hover t)
  (setq lsp-completion-show-detail t)
  (setq lsp-completion-show-kind t))
;; //(setq lsp-auto-guess-root t)
(defun lsp-ui-sideline--compute-height nil '(height unspecified))

(use-package! lsp-nix
  :ensure lsp-mode
  :after
  (lsp-mode)
  :demand t
  :custom
  (lsp-nix-nil-formatter
   ["alejandra"]))