anchor.diff:  
   , alsa-lib
   , libx11
  +, libxi
  +, libxinerama
  +, libxrandr
   , xorg
   
   , channel ? "0.15"
  
positive.code:     alsa-lib
      libx11
      xorg.libXcursor
      xorg.libXi
      xorg.libXinerama
      xorg.libXrandr
    ];
  
    installPhase = ''
  
negative.code: let
    sources = {
      "0.15" = {
        version = "0.15.34";
        sha256_alpha = "9ae0de043baf70a1e008c0859b16a859d165fe33951f20c8bf7c5500369f115e";
        sha256_headless = "e0d2a79dfa587d8d01ec514d4e6ed7ae9f353a47c49a2a471bd34489280327d4";
      };
    };
    source = sources."${channel}";
  