anchor.diff:  
   let
   
  +  inherit (pkgs.stdenv.hostPlatform) isDarwin;
  +
     cfg = config.programs.firefox;
  +
  +  mozillaConfigPath =
  +    if isDarwin
  +    then "Library/Application Support/Mozilla"
  +    else ".mozilla";
  +
  +  firefoxConfigPath =
  +    if isDarwin
  +    then "Library/Application Support/Firefox"
  +    else "${mozillaConfigPath}/firefox";
  +
  +  profilesPath =
  +    if isDarwin
  +    then "${firefoxConfigPath}/Profiles"
  +    else firefoxConfigPath;
   
     extensionPath = "extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}";
   
  
positive.code:     flip mapAttrs' cfg.profiles (_: profile:
        nameValuePair "Profile${toString profile.id}" {
          Name = profile.name;
          Path = profile.path;
          IsRelative = 1;
          Default = if profile.isDefault then 1 else 0;
        }
  
negative.code:         bcfg = setAttrByPath [browserName] fcfg;
  
          package =
            if isDarwin then
              cfg.package
            else if versionAtLeast config.home.stateVersion "19.09" then
              cfg.package.override { cfg = fcfg; }
            else
              (pkgs.wrapFirefox.override { config = bcfg; }) cfg.package { };
        in
          [ package ];
  
      home.file = mkMerge (
        [{
          "${mozillaConfigPath}/${extensionPath}" = mkIf (cfg.extensions != []) (
            let
              extensionsEnv = pkgs.buildEnv {
                name = "hm-firefox-extensions";
  