anchor.diff:                             "--enable-strip" ])
     ++ lib.optional enableOfficialBranding "--enable-official-branding"
     ++ extraConfigureFlags;
  +
  +  # Before 58 we have to run `make -f client.mk configure-files` at
  +  # the top level, and then run `./configure` in the obj-* dir (see
  +  # above), but in 58 we have to instead run `./mach configure` at the
  +  # top level and then run `make` in obj-*. (We can also run the
  +  # `make` at the top level in 58, but then we would have to `cd` to
  +  # `make install` anyway. This is ugly, but simple.)
  +  postConfigure = lib.optionalString (lib.versionAtLeast version "58") ''
  +    cd obj-*
  +  '';
   
     preBuild = lib.optionalString (enableOfficialBranding && isTorBrowserLike) ''
       buildFlagsArray=("MOZ_APP_DISPLAYNAME=Tor Browser")
  
positive.code:     "--disable-gconf"
      "--enable-default-toolkit=cairo-gtk${if gtk3Support then "3" else "2"}"
    ]
    ++ lib.optionals (stdenv.lib.versionAtLeast version "56" && !stdenv.hostPlatform.isi686) [
      # on i686-linux: --with-libclang-path is not available in this configuration
      "--with-libclang-path=${llvmPackages.libclang}/lib"
      "--with-clang-path=${llvmPackages.clang}/bin/clang"
    ]
    ++ lib.optionals (stdenv.lib.versionAtLeast version "57") [
      "--enable-webrender=build"
    ]
  
  
negative.code:     rm -f configure
      rm -f js/src/configure
      rm -f .mozconfig*
    '' + (if lib.versionAtLeast version "58"
    # this will run autoconf213
    then ''
      configureScript="$(realpath ./mach) configure"
    '' else ''
      make -f client.mk configure-files
      configureScript="$(realpath ./configure)"
    '') + ''
      cxxLib=$( echo -n ${gcc}/include/c++/* )
      archLib=$cxxLib/$( ${gcc}/bin/gcc -dumpmachine )
  
      test -f layout/style/ServoBindings.toml && sed -i -e '/"-DMOZ_STYLO"/ a , "-cxx-isystem", "'$cxxLib'", "-isystem", "'$archLib'"' layout/style/ServoBindings.toml
    '' + lib.optionalString googleAPISupport ''
      # Google API key used by Chromium and Firefox.
      # Note: These are for NixOS/nixpkgs use ONLY. For your own distribution,
      # please get your own set of keys.
      echo "AIzaSyDGi15Zwl11UNe6Y-5XW_upsfyw31qwZPI" > $TMPDIR/ga
      configureFlagsArray+=("--with-google-api-keyfile=$TMPDIR/ga")
    '' + lib.optionalString (lib.versionOlder version "58") ''
      cd obj-*
    '';
  
  