Nix search path entry does not exist

[KaiserKarel]

I'm getting the following error:

warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignorg
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I), at /home/karel3

Any advice on how to use nix build inside the vm?

[Mic92]

It looks like you do not have a valid NIX_PATH set and/or or nix-channels is not set up in the VM.

If you don't to set up one each time you can use one of the following methods:

$ export NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs/archive/refs/heads/nixpkgs-unstable.tar.gz
$ nix-build

or

$ nix-build -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/refs/heads/nixpkgs-unstable.tar.gz

There is probably also a way on how to do this declarative in the NixOS configuration of the VM.
I think our installation tests in nixpkgs had some examples.

[KaiserKarel]

I'm thinking this might also be due to my permsissions? When I create a different user in the vm.nix file, in the wheel group, and try to use sudo, I get the following error:

sudo: error in /etc/sudo.conf, line 0 while loading plugin "sudoers_policy"
sudo: /nix/store/b0f7wna41zs504lqy1ir7s1fknr893ll-sudo-1.9.6p1/libexec/sudo/sudoers.so must be owned by uid 0
sudo: fatal error, unable to load plugins

My NIX_PATH does is valid for the user karel, but not root:

warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring # does not exist
`/nix/var/nix/profiles/per-user/karel/channels'  # does exist

For context, here is the configuration file:

 { lib, pkgs, ... }: {
  boot.kernelPackages = pkgs.linuxPackages_latest;
  services.openssh.enable = true;

  virtualisation = {
    cores = 6;
    memorySize = "16G";
    docker.enable = true;
    graphics = false;
  };



  users.users = let
    user = builtins.getEnv "USER";
    keys = map (key: "${builtins.getEnv "HOME"}/.ssh/${key}") ["id_rsa.pub" "id_ecdsa.pub" "id_ed25519.pu>
    home = builtins.getEnv "HOME";
  in {
   ${user} = {
    isNormalUser = true;
    extraGroups = ["wheel" "networkmanager" "docker"];
    openssh.authorizedKeys.keyFiles = lib.filter builtins.pathExists keys;
    home = home;
    initialHashedPassword = "";
   };
  };

[KaiserKarel]

Or am I not supposed to use users different from root with nixos-shell?

[Mic92]

I have not tested this with different users but when I log into the vm and run as root

$ sudo nix-channel --add https://github.com/NixOS/nixpkgs/archive/refs/heads/nixpkgs-unstable.tar.gz nixos
$ ls -la /nix/var/nix/profiles/per-user/root/
lrwxrwxrwx 15 root 12 Apr 11:56  channels -> channels-1-link
lrwxrwxrwx 60 root 12 Apr 11:56  channels-1-link -> /nix/store/67f8bhzzq3jbahrmsq77i7g2fdyj1dbm-user-environment

I see a channel being created.

[KaiserKarel]

Hmmm, I'll have a look at this more this weekend. We were hoping to use nixos-shell as dev environments, with services running etc; so running everything as root should work, although our security guy was not too happy ;)

[Mic92]

It should also work without root. I just have not tried it. You need to create a different channel anyway afterwards. Instead of channels you can also set NIX_PATH globally in the vm using this nixos configuration.

{ pkgs, ... }: {
      nix.nixPath = [
        "nixpkgs=${pkgs.path}"
      ];
}