Hey gdenn,
Sourcing .bash_profile is the right thing to do, as it's there that the path is augmented to add gcloud and its completions. You should check if another file, like ~/.bashrc is being sourced, and if necessary, add "source ~/.bash_profile" in there, to ensure it is sourced every time and doesn't need to be run as a command by hand in future.
I found a link online to a
github issue where a user saw similar issues (I found it by googling the error message, a common and very useful means to debug issues!) on Mac OS X. Check the thread for advice on possible solutions, such as installing bash_completion. Be aware that this isn't a link to Google documentation so you assume responsibility for it, and I'm far from guaranteeing it as a solution. But it's one possible avenue to look into.
Another issue the link raises is whether or not you're even running a bash shell. Zsh has a different syntax and you may need to figure out how to augment your path and set up completion. There's
a gist on github purporting to show this, but note that this is also not one of our links and I can't vouch for it - you'll have to study it yourself for security, applicability, etc.
Let me know if you have any further questions, and how all this works out for you; I'll be happy to help!
Nick
Cloud Platform Community Support