anchor.diff:               ++ stdenv.lib.optional stdenv.isDarwin libiconv;
     nativeBuildInputs = [ tcl ];
   
  -  doCheck = true;
  +  doCheck = stdenv.hostPlatform == stdenv.buildPlatform;
   
     checkTarget = "test";
   
  -  preCheck = ''
  +  preCheck = stdenv.lib.optional doCheck ''
       export TCLLIBPATH="${tcllib}/lib/tcllib${tcllib.version}"
     '';
     configureFlags = if withJson then  "--json" else  "";
  
positive.code: {stdenv, libiconv, fetchurl, zlib, openssl, tcl, readline, sqlite, ed, which
  , tcllib, withJson ? true}:
  
  stdenv.mkDerivation rec {
    name = "fossil-${version}";
  
negative.code:     mkdir -p $out/bin
      INSTALLDIR=$out/bin make install
    '';
  
    meta = {
      description = "Simple, high-reliability, distributed software configuration management";
  