anchor.diff: -{ stdenv, fetchFromGitHub, overrideCC, gcc5
  +{ stdenv, fetchFromGitHub
   , makeWrapper, unzip, which
   , curl, tzdata, gdb, darwin
  -, callPackage, targetPackages
  -, bootstrapVersion ? false
  -, version ? "2.079.1"
  -, dmdSha256 ? "0mlk095aw94d940qkymfp85daggiz3f0xv598nlc7acgp6408kyj"
  -, druntimeSha256 ? "18r8gwvb54ar80j5155wx0qbqq4w56hqmbf6wap20xwijg2rw90g"
  -, phobosSha256 ? "1x5v1ln51nr8x2vyki864160bakdyq0acmvbfv7jcipaj2w3m9bb"
  +, callPackage, targetPackages, ldc
  +, version ? "2.081.1"
  +, dmdSha256 ? "1xdz7p0pdzwkn57ai93mavgdkd8xb1sr2brlc6y3c12x84h43s8z"
  +, druntimeSha256 ? "1vl8ag6rjvqqmc5bn5jk3yfynjb9ggy3hw1awwl7c76bq4f7nbif"
  +, phobosSha256 ? "0h1jdc3yai1l42bxjdlyi9hf9qadh76v925rjk2q4ibv2fzl56b7"
   }:
   
   let
  -
  -  bootstrapDmd = if !bootstrapVersion then
  -    # Versions 2.070.2 and up require a working dmd compiler to build so we just
  -    # use the last dmd without any D code to bootstrap the actual build.
  -    callPackage ./default.nix {
  -      stdenv = if stdenv.hostPlatform.isDarwin then
  -                 stdenv
  -               else
  -                 # Doesn't build with gcc6 on linux
  -                 overrideCC stdenv gcc5;
  -      bootstrapVersion = true;
  -      version = "2.067.1";
  -      dmdSha256 = "0fm29lg8axfmzdaj0y6vg70lhwb5d9rv4aavnvdd15xjschinlcz";
  -      druntimeSha256 = "1n2qfw9kmnql0fk2nxikispqs7vh85nhvyyr00fk227n9lgnqf02";
  -      phobosSha256 = "0fywgds9xvjcgnqxmpwr67p3wi2m535619pvj159cgwv5y0nr3p1";
  -    }
  -  else
  -    "";
   
     dmdBuild = stdenv.mkDerivation rec {
       name = "dmdBuild-${version}";
  
positive.code:     else
        stdenv.hostPlatform.parsed.kernel.name;
      top = "$(echo $NIX_BUILD_TOP)";
      pathToDmd = if bootstrapVersion then
        "${top}/dmd/src/dmd"
      else
        "${top}/dmd/generated/${osname}/release/${bits}/dmd";
  
      # Buid and install are based on http://wiki.dlang.org/Building_DMD
      buildPhase = ''
          cd dmd
          make -j$NIX_BUILD_CORES -f posix.mak INSTALL_DIR=$out
          cd ../druntime
          make -j$NIX_BUILD_CORES -f posix.mak PIC=1 INSTALL_DIR=$out DMD=${pathToDmd}
          cd ../phobos
          make -j$NIX_BUILD_CORES -f posix.mak PIC=1 INSTALL_DIR=$out DMD=${pathToDmd} TZ_DATABASE_DIR=${tzdata}/share/zoneinfo/
          cd ..
      '';
  
      doCheck = !bootstrapVersion;
  
      checkPhase = ''
          cd dmd
  
negative.code:         make -j$NIX_BUILD_CORES -f posix.mak unittest PIC=1 DMD=${pathToDmd} BUILD=release
          cd ..
      '';
  
      extension = if stdenv.hostPlatform.isDarwin then "a" else "{a,so}";
      
      dontStrip = true;
  
      installPhase = ''
  