"please lose your entire scroll buffer before this works, even though there's a way to use brew right now without doing that" isn't really going to win anyone favours. In cases like these: just ask the user what they want to do.
> For brew to be available as command, brew needs to update your path and [bash/zsh/etc] profile. Please select how you wish to continue:
> 1. Please do this for me
> 2. Explain what you're about to do first, then ask me again.
> 3. No thanks. I'll do this myself.
And then you also make sure there's a runtime flag or even env var that can be used to override this, for admins who need to install brew as part of mass deploys.
> For brew to be available as command, brew needs to update your path and [bash/zsh/etc] profile. Please select how you wish to continue:
> 1. Please do this for me
> 2. Explain what you're about to do first, then ask me again.
> 3. No thanks. I'll do this myself.
And then you also make sure there's a runtime flag or even env var that can be used to override this, for admins who need to install brew as part of mass deploys.