Yes, the issue is specific to running bitrise cli locally on my Mac. I downloaded the bitrise.yml file and copied it to the root of my project. (Builds are running just fine on Bitrise.io, this is my first attempt at using the cli)
I ran bitrise setup
Then just running my birtise workflow.
You can define your environments in a .bitrise.secrets.yml file, if the file is placed in the same directory where your bitrise.yml is and you run bitrise cli commands in this directory, bitrise run will use this envs automatically.
Otherwise you can specify the secrets file path: bitrise run --inventory [PATH/TO/YOUR/.bitrise.secrets.yml]
Note: you should gitignore this file, since it is related to your local environment.