Fish session vars not present as expected

[rrrnld]

Issue description

I have a couple of lines in my ~/.config/nixpkgs/home.nix that manipulate session variables. I expected these to be present in my fish terminal sessions (fish is my default shell), but they're not.

I installed foreign-env manually after previously realizing that it wasn't getting installed automatically. My complete fish config looks like this:

{
  # ...
  home.sessionPath = [ "$HOME/.emacs.d/bin" "$HOME/.local/bin" ];
  home.sessionVariables = {
    MOZ_ENABLE_WAYLAND = "1";
    EDITOR = "${pkgs.neovim}/bin/nvim";
  };

  programs = {
    fish = {
      enable = true;
      plugins = [
        {
          # required to manage shell environment through home-manager
          name = "foreign-env";
          src = pkgs.fish-foreign-env;
        }

        {
          name = "bang-bang";
          src = pkgs.fetchFromGitHub {
            owner = "oh-my-fish";
            repo = "plugin-bang-bang";
            rev = "f969c618301163273d0a03d002614d9a81952c1e";
            hash = "sha256-A8ydBX4LORk+nutjHurqNNWFmW6LIiBPQcxS3x4nbeQ=";
          };
        }

        {
          name = "fasd";
          src = pkgs.fetchFromGitHub {
            owner = "oh-my-fish";
            repo = "plugin-fasd";
            rev = "98c4c729780d8bd0a86031db7d51a97d55025cf5";
            hash = "sha256-8JASaNylXAGnWd2IV88juk73b8eJJlVrpyiRZUwHGFQ=";
          };
        }

        {
          name = "pure";
          src = pkgs.fetchFromGitHub {
            owner = "pure-fish";
            repo = "pure";
            rev = "9d17b2780165572bc6c181cd0e7c5d6dd13be5c1";
            hash = "sha256-60NKbQurOxqjnXmluDCh+C/b/z52IYK2g4CeZASWyJk=";
          };
        }
      ];

      functions = {
        mkd = {
          body = "mkdir -p $argv[1]; and cd $argv[1]";
        };
      };

      shellAliases = {
        e = "emacsclient";

        docker = "podman";
        docker-compose = "podman-compose";
        pbcopy = "xsel --clipboard -i";
        pbpaste = "xsel --clipboard -o";
        open = "xdg-open";
        rm = "rm -i";

        dokku = "ssh dokku@arnes.space -t";

        # git aliases
        ga = "git add";
        gc = "git commit";
        "gc!" = "git commit --amend";
        "gc!!" = "git commit --amend --no-edit";
        gco = "git checkout";
        gd = "git diff --ignore-all-space";
        gdw = "git diff --ignore-all-space --color-words";
        glg = "git log --oneline";
        gp = "git push";
        gs = "git status";
        gss = "git status --short";

        urlencode = "jq -sRr @uri";
        benjamins = "nvim +(wc -l ~/ledger/finances-2021.ledger | cut -d' ' -f1) ~/ledger/finances-2021.ledger";
      };

      # tomorrow night theme
      loginShellInit = ''
        set -L
        set -U fish_color_normal normal
        set -U fish_color_command 81a1c1
        set -U fish_color_redirection b48ead
        set -U fish_color_quote a3be8c
        set -U fish_color_end 88c0d0
        set -U fish_color_user brgreen
        set -U fish_color_param eceff4
        set -U fish_pager_color_progress brwhite --background=cyan
        set -U fish_pager_color_prefix white --bold --underline
        set -U fish_pager_color_description B3A06D yellow
        set -U fish_pager_color_completion normal
        set -U fish_color_cancel -r
        set -U fish_color_match --background=brblue
        set -U fish_color_error ebcb8b
        set -U fish_color_selection white --bold --background=brblack
        set -U fish_color_search_match bryellow --background=brblack
        set -U fish_color_history_current --bold
        set -U fish_color_operator 00a6b2
        set -U fish_color_escape 00a6b2
        set -U fish_color_cwd green
        set -U fish_color_cwd_root red
        set -U fish_color_valid_path --underline
        set -U fish_color_autosuggestion 4c566a
        set -U fish_color_comment 434c5e
        set -U fish_color_host normal
      '';

      interactiveShellInit = ''
        # FIXME: Need to explicitly call this to show new lines between prompts
        # in pure
        _pure_prompt_new_line
      '';
    };
  };
}

My ~/.nix-profile/etc/profile.d/hm-session.vars.sh looks like this:

# Only source this once.
if [ -n "$__HM_SESS_VARS_SOURCED" ]; then return; fi
export __HM_SESS_VARS_SOURCED=1

export EDITOR="/nix/store/hwh9hdpa75mhq44ra5978459hjyf1y4v-neovim-0.4.4/bin/nvim"
export FZF_CTRL_T_COMMAND="fd --type f"
export FZF_DEFAULT_OPTS="--height 80% --reverse --prompt \"❯ \" --pointer \"❯ \""
export MOZ_ENABLE_WAYLAND="1"
export MSMTP_LOG="/home/arne/.local/share/msmtp/queue.log"
export MSMTP_QUEUE="/home/arne/.local/share/msmtp/queue"
export NMBGIT="/home/arne/.local/share/notmuch/nmbug"
export NOTMUCH_CONFIG="/home/arne/.config/notmuch/notmuchrc"
export PASSWORD_STORE_DIR="/home/arne/.local/share/password-store"
export PATH="$PATH${PATH:+:}$HOME/.emacs.d/bin:$HOME/.local/bin"

Checking these variables in a Fish session gives the following result:

$ echo $__HM_SESS_VARS_SOURCED
1
$ echo $EDITOR
nano
$ # from $FZF_CTRL_T_COMMAND until $PASSWORD_STORE_DIR, all are set as expected
$ echo $PATH
/run/wrappers/bin /home/arne/.nix-profile/bin /etc/profiles/per-user/arne/bin /nix/var/nix/profiles/default/bin /run/current-system/sw/bin

Meta

Maintainer CC

@meck

Technical detail

 - system: `"x86_64-linux"`
 - host os: `Linux 5.4.112, NixOS, 20.09.4025.dc326c78a93 (Nightingale)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.4pre20210326_dd77f71`
 - channels(arne): `"home-manager-20.09"`
 - channels(root): `"nixos-20.09.4025.dc326c78a93, nixos-hardware, nixos-unstable-21.05pre285574.8e4fe32876c"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

[rycee]

Curious. Unfortunately I don't know much about fish but did you log out and back in after changing the configuration?

[rrrnld]

Ha… Just as I said to myself "of course I did!" and rebooted just to make sure, the problem went away. So thanks for the reminder!

[rycee]

Glad it worked out. Also, thanks for making such a detailed report!

[meck]

Any reason you cc'd me as maintainer?

[rrrnld]

Any reason you cc'd me as maintainer?

Yes, the issue template suggested to CC the last person that worked on the module when in doubt. Sorry if that was a mistake!

[meck]

Yes, the issue template suggested to CC the last person that worked on the module when in doubt. Sorry if that was a mistake!

No problem! just wanted to se if I was listed somewhere.

[theotheroracle]

is there a reason that restarting the shell doesn't reload the variables ? if it's sourcing the hm-session.vars.fish file every time, why don't the variables update until logout and login ? having to logout and login while testing variables is pretty tedious, and if possible to avoid, would be nice