anchor.diff:  
   let
   
  -  inherit (pkgs) plymouth;
  -  inherit (pkgs) nixos-icons;
  +  inherit (pkgs) plymouth nixos-icons;
   
     cfg = config.boot.plymouth;
   
  
positive.code:       mkdir -p $out/share/plymouth/themes
        cp ${plymouth}/share/plymouth/plymouthd.defaults $out/share/plymouth
  
        # copy themes into working directory for patching
        mkdir themes
        # use -L to copy the directories proper, not the symlinks to them
        cp -r -L ${themesEnv}/share/plymouth/themes/{text,details,${cfg.theme}} themes
  
        # patch out any attempted references to the theme or plymouth's themes directory
        chmod -R +w themes
        find themes -type f | while read file
        do
          sed -i "s,/nix/.*/share/plymouth/themes,$out/share/plymouth/themes,g" $file
        done
  
        cp -r themes/* $out/share/plymouth/themes
        cp ${cfg.logo} $out/share/plymouth/logo.png
  
        mkdir -p $out/share/fonts
        cp ${cfg.font} $out/share/fonts
        mkdir -p $out/etc/fonts
  
negative.code:       };
  
        theme = mkOption {
          default = "bgrt";
          type = types.str;
          description = ''
            Splash screen theme.
  