anchor.diff:      url = "https://static.rust-lang.org/dist/rustc-${version}-src.tar.gz";
       sha256 = "1hrqprybhkhs6d9b5pjskfnc5z9v2l2gync7nb39qjb5s0h703hj";
     };
  -
  -  # Provide the compiler-rt sources needed for profiling.
  -  preConfigure = ''
  -    mkdir src/llvm-project/compiler-rt
  -    tar xf ${llvmPackages.compiler-rt.src} -C src/llvm-project/compiler-rt --strip-components=1
  -  '';
   
     __darwinAllowLocalNetworking = true;
   
  
positive.code: { stdenv, removeReferencesTo, pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget
  , fetchurl, file, python2, tzdata, ps
  , llvmPackages_7, darwin, git, cmake, rustPlatform
  , which, libffi, gdb
  , withBundledLLVM ? false
  }:
  
negative.code:   inherit (stdenv.lib) optional optionalString;
    inherit (darwin.apple_sdk.frameworks) Security;
  
    llvmSharedForBuild = pkgsBuildBuild.llvm_7.override { enableSharedLibraries = true; };
    llvmSharedForHost = pkgsBuildHost.llvm_7.override { enableSharedLibraries = true; };
    llvmSharedForTarget = pkgsBuildTarget.llvm_7.override { enableSharedLibraries = true; };
  
    # For use at runtime
    llvmShared = llvm_7.override { enableSharedLibraries = true; };
  in stdenv.mkDerivation rec {
    pname = "rustc";
    version = "1.37.0";
  
  