I’ve been always seeing the “Already up-to-date” message after running
After a few weeks without a single update I have become enough suspicious to start googling about this issue.
I was able to find a notice saying:
If Homebrew was updated on Aug 10-11th 2016 and
brew update always says “Already up-to-date”. You need to run:
cd $(brew --repo) && git fetch && git reset --hard origin/master && brew update