Received the following errors when doing brew update on mountain lion:
error: The following untracked working tree files would be overwritten by merge:
Library/Formula/platypus.rb
Please move or remove them before you can merge.
Aborting
Error: Failure while executing: git pull -q origin refs/heads/master:refs/remotes/origin/master
A solution found on Stackoverflow
cd /usr/local
git fetch origin
git reset --hard origin/master