anchor.diff:  { stdenv, fetchFromGitHub, file, curl, pkgconfig, python, openssl, cmake, zlib
   , makeWrapper, libiconv, cacert, rustPlatform, rustc, libgit2, darwin
   , version, srcSha, cargoSha256
  -, patches ? []}:
  +, patches ? [] }:
  +
  +let
  +  inherit (darwin.apple_sdk.frameworks) CoreFoundation;
  +in
   
   rustPlatform.buildRustPackage rec {
     name = "cargo-${version}";
  
positive.code:     wrapProgram "$out/bin/cargo" \
        --suffix PATH : "${rustc}/bin" \
        --set CARGO_HTTP_CAINFO "${cacert}/etc/ssl/certs/ca-bundle.crt" \
        --set SSL_CERT_FILE "${cacert}/etc/ssl/certs/ca-bundle.crt" \
        ${stdenv.lib.optionalString stdenv.isDarwin ''--suffix DYLD_LIBRARY_PATH : "${rustc}/lib"''}
    '';
  
    checkPhase = ''
  
negative.code: 
    nativeBuildInputs = [ pkgconfig ];
    buildInputs = [ file curl python openssl cmake zlib makeWrapper libgit2 ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ CoreFoundation libiconv ];
  
    LIBGIT2_SYS_USE_PKG_CONFIG=1;
  
    # FIXME: Use impure version of CoreFoundation because of missing symbols.
    # CFURLSetResourcePropertyForKey is defined in the headers but there's no
    # corresponding implementation in the sources from opensource.apple.com.
    preConfigure = stdenv.lib.optionalString stdenv.isDarwin ''
      export NIX_CFLAGS_COMPILE="-F${CoreFoundation}/Library/Frameworks $NIX_CFLAGS_COMPILE"
    '';
  
    postInstall = ''
      # NOTE: We override the `http.cainfo` option usually specified in
  