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