Found the fix! It’s an error in /usr/local/lib/node_modules/ionic-app-lib/lib/config.js
You’ll want to edit the file, .eg:
sudo nano /usr/local/lib/node_modules/ionic-app-lib/lib/config.js
And change line 7:
CONFIG_FILE: '.ionic/ionic.config',
To have a slash after the dot:
CONFIG_FILE: './ionic/ionic.config',
Then save the file, and try running an ionic command:
ionic