anchor.diff: -{ alsa-lib, at-spi2-atk, at-spi2-core, atk, autoPatchelfHook, cairo, cups
  -, dbus, electron_9, expat, fetchurl, gdk-pixbuf, glib, gtk3, lib
  -, libappindicator-gtk3, libdbusmenu-gtk3, libuuid, makeWrapper
  -, nspr, nss, pango, squashfsTools, stdenv, systemd, xorg
  +{ alsa-lib
  +, at-spi2-atk
  +, at-spi2-core
  +, atk
  +, autoPatchelfHook
  +, cairo
  +, cups
  +, dbus
  +, electron_9
  +, expat
  +, fetchurl
  +, gdk-pixbuf
  +, glib
  +, gtk3
  +, lib
  +, libappindicator-gtk3
  +, libdbusmenu-gtk3
  +, libuuid
  +, makeWrapper
  +, nspr
  +, nss
  +, pango
  +, squashfsTools
  +, stdenv
  +, systemd
  +, xorg
   }:
   
   let
  
positive.code: 
    src = fetchurl {
      url = "https://api.snapcraft.io/api/v1/snaps/download/H8ZpNgIoPyvmkgxOWw5MSzsXK1wRZiHn_${rev}.snap";
      sha256 = "10az47cc3lgsdi0ixmmna08nqf9xm7gsl1ph00wfwrxzsi05ygx3";
    };
  
    nativeBuildInputs = [ autoPatchelfHook makeWrapper squashfsTools ];
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "authy";
    # curl -H 'X-Ubuntu-Series: 16' 'https://api.snapcraft.io/api/v1/snaps/details/authy?channel=stable' | jq '.download_url,.version'
    version = "2.1.0";
    rev = "9";
  
    buildInputs = [
      alsa-lib
  