anchor.diff:  , pcre, expat, boost, mpfr, git, texinfo }:
   
   let
  -  rev = "cf35984971341b8a8688";
  +  rev = "d2915c66";
   in
   stdenv.mkDerivation {
     name = "ledger3-2012.01.${rev}";
  
positive.code:   src = fetchgit {
      url = "git://github.com/jwiegley/ledger.git";
      inherit rev;
      sha256 = "4078983db9fc8d232fa71a31b47e505c531971b4515d6ef723e7d333a2352d2a";
    };
  
    buildInputs = [
  
negative.code: 
    buildPhase = ''
      sed -i acprep \
        -e 's|search_prefixes = .*|search_prefixes = ["${boost}"]|' \
        -e 's|/usr/bin/python|${python}/bin/python|'
      export MAKEFLAGS="-j$NIX_BUILD_CORES -l$NIX_BUILD_CORES"
      python acprep update --no-pch --prefix=$out
    '';
  