When working on OpenWhisk, I discovered that it needed a different Java to the one I had installed. Looking around the Internet, I discovered jenv which shouldn't have surprised me as I use pyenv and I'm aware of rbenv too. As I use Homebrew, these are the commands I used. Firstly install jenv, the latest Java (15 at this time) and any other versions you need. Java 8 and 12 in this example: $ brew… continue reading.