Get fish shell to work with gcloud command line tools?

What worked for me was just using bass. Check it out: https://github.com/edc/bass

Just take the lines that gcloud adds to your bash_profile, and prepend bass to them in your .config/fish/config.fish file, as follows:

# The next line updates PATH for the Google Cloud SDK.
bass source '/Users/hunter/bin/google-cloud-sdk/path.bash.inc'

# The next line enables shell command completion for gcloud.
bass source '/Users/hunter/bin/google-cloud-sdk/completion.bash.inc'

As of today, I was able just to do

1. brew install --cask google-cloud-sdk
2. Added source /usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/path.fish.inc to my ~/.config/fish/config.fish
3. Clone https://github.com/aliz-ai/google-cloud-sdk-fish-completion then run install.sh.