firefox global config not working

[Qubasa]

Describe the bug
I tried to get a global firefox config to work. Mozilla says here https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Enterprise_deployment_before_60 that a file has to be placed to firefox-unwrapped/lib/firefox/defaults/pref/autoconfig.js or firefox-unwrapped/lib/firefox/defaults/pref/channel-prefs.js and firefox-unwrapped/lib/firefox/mozilla.cfg.

To achieve that I needed to write these files into another derivation and symlink everything else (except firefox-unwrapped/bin/firefox which has been re-wrapped). After successfully doing so it still doesn't load the config files.

{ config, pkgs, ... }:

let


myFirefox = pkgs.runCommand "myfirefox" {
  buildInputs = [ pkgs.makeWrapper pkgs.xorg.lndir ];
} ''

mkdir $out

# Link every top-level folder from pkgs.hello to our new target
lndir -silent ${pkgs.firefox-unwrapped} $out

# Except the bin folder
rm -r $out/bin
mkdir $out/bin

makeWrapper $out/lib/firefox/firefox $out/bin/firefox \
  --add-flags "-t"

mkdir -p $out/lib/firefox/browser/defaults/preferences
 mkdir -p $out/lib/firefox/defaults/pref
 mkdir -p $out/bin

# Generate autoconfig.js for firefox v61+
echo '// Any comment. You must start the file with a single-line comment!
pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0);
' > "$out/lib/firefox//browser/defaults/preferences/autoconfig.js"

rm $out/lib/firefox/defaults/pref/channel-prefs.js
# Generate autoconfig.js for firefox v60-
echo '// Any comment. You must start the file with a single-line comment!
pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0);
pref("app.update.channel", "test");
' > "$out/lib/firefox/defaults/pref/channel-prefs.js"

# Generate preference file
echo '// Any comment. You must start the file with a single-line comment!
lockPref("browser.startup.homepage", "https://youtube.com");
' > "$out/lib/firefox/mozilla.cfg"

'';


# firefox_config = pkgs.writeText "auto" ''


# '';

in {


# system.activationScripts.copyConfig = ''
# '';


environment.systemPackages = with pkgs; [
  myFirefox
  ];
}

I think to address this issue there has to be an option in the firefox package that is overridable with the config a user wants that places the config file directly into the firefox derivation.

Or a firefox patch that enable absolute paths for the config.

Metadata

• system: "x86_64-linux"
• host os: Linux 4.19.64, NixOS, 19.03.173251.56d94c8c69f (Koi)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.2.2
• channels(root): "nixos-19.03.173251.56d94c8c69f, nixos-unstable-19.09pre186820.bf39fc17d46"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

[xaverdh]

See #57554 and #58195 for my attempts at implementing this.

[Qubasa]

So nice