Nix-direnv seemingly corrupting astro's vite server

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1

Hello,

I’ve recently run into a particularly weird issue, I was working on a standard Astro v7 project when I noticed that starting the development server with resulted in a consistent, 20s+ launch time. I tried both bun and node but both had the same issue. Doing a build and then preview worked in about 4s.

I decided to dig deeper and managed to trace the issue to the function vite.createServer, specifically down to configureServer hooks, but that wasn’t particularly helpful. I ignored the issue and ran development via build and preview for some time until I decided to work on resolving it by initializing multiple vite projects (nextjs, svelte, astro) both with nodejs and bun, to my surprise there were no issues on any of them.
I was progressively tracing each one of the specific changes my project had compared to the base Astro project but nothing changed the result, until my storage filled and I ran nh clean all. After that, I started the dev server for my project (I was using a shell provided by nix develop at the time, which didn’t trigger direnv as I had only configured the fish direnv hook but not the bash one) and it launched in 4s. I then decided to start fish, which in turn loaded direnv, making the launch time 20s+ again. I went back to the nix develop provided shell and tried running it from there, only to see 20s+ start time again.

After a large amount of trying things, I managed to reduce the issue to:

  • Seems to happen only with Astro, independent of runtime
  • Clearing gcroots and then running the dev server via nix develop or nix-shell both work
  • The moment a direnv provided shell loads (and installs bun / node), the start time turns 20s+
  • The issue is project dependent, meaning that loading a direnv provided shell corrupts only that specific project
  • A corrupted project will affect any bun / node installation that is added to the path, this means that even if I source a external flake via --impure, the provided runtimes will still be affected

I’m not sure as to what information I could attach regarding system configuration, as I think it’s mostly unrelated, still:

nixos-version
26.11.20260629.b5aa0fb (Zokor)

(via home-manager)
programs.direnv = {
  enable = true;
  nix-direnv.enable = true;
};

(the flake for the project)
{
  description = "A flake";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-26.05";
    nixpkgs-unstable.url = "github:nixos/nixpkgs?ref=nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs =
    {
      nixpkgs,
      nixpkgs-unstable,
      flake-utils,
      ...
    }:
    flake-utils.lib.eachDefaultSystem (
      system:
      let
        pkgs = import nixpkgs {
          inherit system;
          config.allowUnfree = true;
        };
        unstable = import nixpkgs-unstable {
          inherit system;
          config.allowUnfree = true;
        };
      in
      {
        devShells.default = pkgs.mkShell {
          packages = pkgs.lib.flatten [
            (with pkgs; [
              bun
              nodejs
              pnpm
            ])
            (with unstable; [
            ])
          ];
          shellHook = "";
          buildInputs = [ pkgs.bashInteractive ];
        };
      }
    );
}

I’m willing to provide any other information requested as this issue really escapes my knowledge about the nix and direnv ecosystem.

Thanks.

1 Like
2

Dumb question, but do you have:

	vite: {
		server: {
			watch: {
				ignored: ["**/.direnv/**"],
			},
		},
	},

(or whatever it is with any new APIs they might have changed) in your astro.config.mjs?defineConfig?

2 Likes
3

Thank you lots, adding it did fix it, thinking about it I guess it makes sense.

1 Like