anchor.diff:      owner = "mypaint";
       repo = "libmypaint";
       rev = "v${version}";
  -    sha256 = "1pxx8fjdabcindxhzgbhg4p7yanl4ihbd8kq71y2nyi9dqsjr2fw";
  +    sha256 = "1fdyywm915mmilfmzp7lz4rnmm05kkw0adrdqpqi4n8icp4d530g";
     };
   
     nativeBuildInputs = [
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "libmypaint";
    version = "1.5.1";
  
    outputs = [ "out" "dev" ];
  
  
negative.code: 
    doCheck = true;
  
    preConfigure = "./autogen.sh";
  
    meta = with stdenv.lib; {
  