Under certain conditions, `brew update` will show doubles. It's a rare
edge-case, but if you have a tap where the name of the formula is identical
with the name of the insalled file, then you see output like this:
==> Updated Formulae
aalib ssh-copy-id
casperjs sshuttle
jack telemachus/anytap/brew-any-tap
mogenerator telemachus/anytap/brew-any-tap
I believe this should fix that.
ClosesHomebrew/homebrew#18495.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>