Mac Mojave PlantUML がどうしても入らないよ

環境: Mac Mojave 10.14

こちらを参考にやりました。
https://qiita.com/kohashi/items/1d2c6e859eeac72ed926

ありゃ

$ brew install plantuml                                                 
Error: An exception occurred within a child process:
  RuntimeError: /usr/local/opt/libffi not present or broken
Please reinstall libffi. Sorry :(

こうしてもだめ。exportもしたけどだめ。

$ brew link libffi --force
Warning: Refusing to link macOS-provided software: libffi
For compilers to find libffi you may need to set:
  export LDFLAGS="-L/usr/local/opt/libffi/lib"

For pkg-config to find libffi you may need to set:
  export PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig"

なので手作業でlinkしました

$ cd /usr/local/opt/
$ ln -s ../Cellar/libffi/3.2.1 libffi
$ ln -s ../Cellar/libtool/2.4.6_1 libtool
$ brew install plantuml
/usr/local/Cellar/plantuml/1.2019.6: 4 files, 7.4MB, built in 12 seconds

ok!! なのかな？ 無事画像も生成できました