localhost:local xxx$ sudo brew update
error: The following untracked working tree files would be overwritten by merge:
Library/Formula/afl-fuzz.rb
Library/Formula/arpon.rb
Library/Formula/bwctl.rb
Library/Formula/chinadns-c.rb
Library/Formula/dsd.rb
Library/Formula/ebook-tools.rb
Library/Formula/epeg.rb
Library/Formula/ffts.rb
Library/Formula/git-review.rb
Library/Formula/i2util.rb
Library/Formula/icdiff.rb
Library/Formula/jooby-bootstrap.rb
Library/Formula/libbpg.rb
Library/Formula/libpointing.rb
Library/Formula/lsh.rb
Library/Formula/mysql-sandbox.rb
Library/Formula/odo.rb
Library/Formula/openh264.rb
Library/Formula/pcsc-lite.rb
Library/Formula/synscan.rb
Library/Formula/vnu.rb
Library/Formula/wakatime-cli.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
sudo git reset --hard origin/master
HEAD is now at 96fe7d1 open-mpi: Set --HEAD to make release build
localhost:local xxx$ sudo brew update
Already up-to-date.