anchor.diff: -{ stdenv, fetchurl, cmake, llvm, curl, tzdata
  +{ stdenv, fetchurl, cmake, ninja, llvm, llvm_8, curl, tzdata
   , python, libconfig, lit, gdb, unzip, darwin, bash
   , callPackage, makeWrapper, targetPackages
   , bootstrapVersion ? false
  -, version ? "1.14.0"
  -, ldcSha256 ? "147vlzzzjx2n6zyz9wj54gj046i1mw5p5wixwzi5wkllgxghyy9c"
  +, version ? "1.15.0"
  +, ldcSha256 ? "1qnfy2q8zkywvby7wa8jm20mlpghn28x6w357cpc8hi56g7y1q6p"
   }:
   
   let
  
positive.code:       patchShebangs .
    ''
  
    + stdenv.lib.optionalString (!bootstrapVersion && stdenv.hostPlatform.isDarwin) ''
        # https://github.com/NixOS/nixpkgs/issues/34817
        rm -r ldc-${version}-src/tests/plugins/addFuncEntryCall
  
negative.code: 
    checkPhase = stdenv.lib.optionalString doCheck ''
      # Build default lib test runners
      ninja -j$NIX_BUILD_CORES all-test-runners
  
      ${fixNames}
  
  