brew update error

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.