anchor.diff:        FPGAs and providing simple tools for analyzing and
         creating bitstream files.
       '';
  -    homepage = http://www.clifford.at/icestorm/;
  -    license = stdenv.lib.licenses.isc;
  +    homepage    = http://www.clifford.at/icestorm/;
  +    license     = stdenv.lib.licenses.isc;
       maintainers = with stdenv.lib.maintainers; [ shell thoughtpolice ];
  -    platforms = stdenv.lib.platforms.linux;
  +    platforms   = stdenv.lib.platforms.linux;
     };
   }
  
positive.code:   };
  
    nativeBuildInputs = [ pkgconfig ];
    buildInputs = [ python3 libftdi ];
    makeFlags = [ "PREFIX=$(out)" ];
  
    # fix icebox_vlog chipdb path. icestorm issue:
    #   https://github.com/cliffordwolf/icestorm/issues/125
    patchPhase = ''
      substituteInPlace ./icebox/icebox_vlog.py \
        --replace /usr/local/share "$out/share"
    '';
  
    meta = {
  
negative.code: { stdenv, fetchFromGitHub
  , pkgconfig, libftdi
  , python3, pypy3
  }:
  
  let
    pypyCompatible = stdenv.isx86_64; /* pypy3 seems broken on i686 */
    pythonPkg      = if pypyCompatible then pypy3 else python3;
    pythonInterp   = if pypyCompatible then "pypy3" else "python3";
  in
  
  stdenv.mkDerivation rec {
    name = "icestorm-${version}";
  