anchor.diff: -{ stdenv, fetchgit, opal, ptlib }:
  +{ stdenv, fetchFromGitHub, opal, ptlib }:
   
   stdenv.mkDerivation rec {
   
  
positive.code: 
    meta = {
      homepage = https://github.com/tmakkonen/sipcmd;
      description = "sipcmd - the command line SIP/H.323/RTP softphone";
      platforms = with stdenv.lib.platforms; linux;
    };
  }
  
negative.code: 
    name = "sipcmd-${rev}";
    
    src = fetchFromGitHub {
      repo = "sipcmd";
      owner = "tmakkonen";
      inherit rev;
      sha256 = "072h9qapmz46r8pxbzkfmc4ikd7dv9g8cgrfrw21q942icbrvq2c";
    };
  
  