anchor.diff:  , libpulseaudio
   , libuuid
   , libxcb
  +, libxkbcommon
   , mesa
   , nspr
   , nss
  
positive.code: 
    pname = "slack";
  
    x86_64-darwin-version = "4.10.3";
    x86_64-darwin-sha256 = "0r77l57vr603xamich4h4gbdd5vdcj0sjs6yjpymfx9s0f98v8bb";
  
    x86_64-linux-version = "4.10.3";
    x86_64-linux-sha256 = "1gnjj2iyk8cwjajg8h9qpmzx10j4qjxjzciq8csg45qfzwkr3drf";
  
    version = {
      x86_64-darwin = x86_64-darwin-version;
  
negative.code:       libpulseaudio
        libuuid
        libxcb
        libxkbcommon
        mesa
        nspr
        nss
  