anchor.diff:      "--enable-jemalloc"
       "--enable-default-toolkit=${default-toolkit}"
       "--with-libclang-path=${llvmPackages.libclang}/lib"
  -    "--with-clang-path=${llvmPackages.clang}/bin/clang"
       "--with-system-nspr"
       "--with-system-nss"
     ]
  -  ++ lib.optional (stdenv.isDarwin) "--disable-xcode-checks"
  +  ++ lib.optional (buildStdenv.isDarwin) "--disable-xcode-checks"
  +  ++ lib.optional (!ltoSupport) "--with-clang-path=${llvmPackages.clang}/bin/clang"
  +  # LTO is done using clang and lld.
  +  # elf-hack is broken when using clang:
  +  # https://bugzilla.mozilla.org/show_bug.cgi?id=1482204
  +  ++ lib.optionals ltoSupport [
  +    "--enable-lto"
  +    "--enable-linker=lld"
  +    "--disable-elf-hack"
  +  ]
   
     ++ flag alsaSupport "alsa"
     ++ flag pulseaudioSupport "pulseaudio"
  
positive.code:       which
      ]
      ++ lib.optional gtk3Support wrapGAppsHook
      ++ lib.optionals stdenv.isDarwin [ xcbuild rsync ]
      ++ extraNativeBuildInputs;
  
    preConfigure = ''
  
negative.code:     gappsWrapperArgs+=(--argv0 "$out/bin/.${binaryName}-wrapped")
    '';
  
    postFixup = lib.optionalString buildStdenv.isLinux ''
      # Fix notifications. LibXUL uses dlopen for this, unfortunately; see #18712.
      patchelf --set-rpath "${lib.getLib libnotify
        }/lib:$(patchelf --print-rpath "$out"/lib/${binaryName}*/libxul.so)" \
  