anchor.diff:  , pcre, expat, boost, mpfr, git, texinfo }:
   
   let
  -  rev = "cf35984971341b8a8688";
  +  rev = "d2915c66";
   in
   stdenv.mkDerivation {
     name = "ledger3-2012.01.${rev}";
  
positive.code: 
    buildPhase = ''
      sed -i acprep \
        -e 's|search_prefixes = .*|search_prefixes = ["${boost}"]|'
      export MAKEFLAGS="-j$NIX_BUILD_CORES -l$NIX_BUILD_CORES"
      python acprep update --no-pch --prefix=$out
    '';
  
negative.code:   src = fetchgit {
      url = "git://github.com/jwiegley/ledger.git";
      inherit rev;
      sha256 = "a489c8b1c48889040d2cebaac1a0019e90acac0b51c9abf7914944dcb4b801e7";
    };
  
    buildInputs = [
  