anchor.diff:  
     installFlags = "prefix=$(out)";
   
  +  preCheck = ''
  +    patchShebangs test/
  +  '';
  +
     enableParallelBuilding = true;
   
     doCheck = true;
  -
  -  preCheck = ''
  -    find test -name "*.pl" -exec sed -ie 's|/usr/bin/\(env[[:space:]]\)\{0,1\}perl|${perl}/bin/perl|' {} +
  -  '';
   
     meta = with stdenv.lib; {
       description = "A C library for reading/writing high-throughput sequencing data";
  
positive.code:     maintainers = [ maintainers.mimadrid ];
    };
  }
  
  
negative.code: 
  stdenv.mkDerivation rec {
    name = "${pname}-${version}";
    pname = "htslib";
    version = "1.6";
  
    src = fetchurl {
      url = "https://github.com/samtools/htslib/releases/download/${version}/${name}.tar.bz2";
      sha256 = "1jsca3hg4rbr6iqq6imkj4lsvgl8g9768bcmny3hlff2w25vx24m";
    };
  
    # perl is only used during the check phase.
    nativeBuildInputs = [ perl ];
  
    buildInputs = [ zlib bzip2 lzma curl ];
  
  