anchor.diff: -{ lib
  +{ stdenv
  +, lib
   , mkDerivation
  -, fetchurl
  -, cmake
  +, fetchFromGitHub
  +, fetchpatch
   , extra-cmake-modules
   
   # common deps
  
positive.code: 
  # client deps
  , qtbase
  , qtmultimedia
  , qtsvg
  , qttools
  
negative.code: # optional server deps
  , libmicrohttpd
  , libsodium
  , withSystemd ? stdenv.isLinux
  , systemd ? null
  
  # options
  , buildClient ? true
  