anchor.diff: -{ stdenv, fetchurl, meson, ninja, wrapGAppsHook, pkgconfig, gettext, itstool, libvirt-glib
  -, glib, gobject-introspection, libxml2, gtk3, gtk-vnc, freerdp, libvirt, spice-gtk, python3
  -, spice-protocol, libsoup, libosinfo, systemd, tracker, tracker-miners, vala
  -, libcap, yajl, gmp, gdbm, cyrus_sasl, gnome3, librsvg, desktop-file-utils
  -, mtools, cdrkit, libcdio, libusb, libarchive, acl, libgudev, libsecret
  -, libcap_ng, numactl, xen, libapparmor, json-glib, webkitgtk, vte, glib-networking
  +{ stdenv
  +, fetchurl
  +, meson
  +, ninja
  +, wrapGAppsHook
  +, pkgconfig
  +, gettext
  +, itstool
  +, libvirt-glib
  +, glib
  +, gobject-introspection
  +, libxml2
  +, gtk3
  +, gtk-vnc
  +, freerdp
  +, libvirt
  +, spice-gtk
  +, python3
  +, spice-protocol
  +, libsoup
  +, libosinfo
  +, systemd
  +, tracker
  +, tracker-miners
  +, vala
  +, libcap
  +, yajl
  +, gmp
  +, gdbm
  +, cyrus_sasl
  +, gnome3
  +, librsvg
  +, desktop-file-utils
  +, mtools
  +, cdrkit
  +, libcdio
  +, libusb
  +, libarchive
  +, acl
  +, libgudev
  +, libsecret
  +, libcap_ng
  +, numactl
  +, xen
  +, libapparmor
  +, json-glib
  +, webkitgtk
  +, vte
  +, glib-networking
   }:
   
  -let
  +stdenv.mkDerivation rec {
  +  pname = "gnome-boxes";
     version = "3.34.1";
  -in stdenv.mkDerivation rec {
  -  pname = "gnome-boxes";
  -  inherit version;
   
     src = fetchurl {
       url = "mirror://gnome/sources/gnome-boxes/${stdenv.lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
  
positive.code:   doCheck = true;
  
    nativeBuildInputs = [
      meson ninja vala pkgconfig gettext itstool wrapGAppsHook gobject-introspection desktop-file-utils python3
    ];
  
    # Required for USB redirection PolicyKit rules file
    propagatedUserEnvPkgs = [ spice-gtk ];
  
    buildInputs = [
      libvirt-glib glib gtk3 gtk-vnc freerdp libxml2
      libvirt spice-gtk spice-protocol libsoup json-glib webkitgtk libosinfo systemd
      tracker tracker-miners libcap yajl gmp gdbm cyrus_sasl libusb libarchive
      gnome3.adwaita-icon-theme librsvg acl libgudev libsecret
      libcap_ng numactl xen libapparmor vte glib-networking
    ];
  
    preFixup = ''
  
negative.code: 
    passthru = {
      updateScript = gnome3.updateScript {
        packageName = pname;
        attrPath = "gnome3.${pname}";
      };
    };
  
  