OSX Install Phalcon Error: undefined method `desc’ for Formulary::Formulae::Zlib:Class

Installing PHP Phalcon framework on Mac OS using this command

brew install php56 php56-phalcon

Home brew may have error like:

==> Installing php56 from homebrew/homebrew-php
Error: undefined method `desc' for Formulary::Formulae::Zlib:Class
Please report this bug:

http://git.io/brew-troubleshooting

/usr/local/Library/Taps/homebrew/homebrew-dupes/zlib.rb:2:in `'

To solve this, run:

brew update

By Keenlio, November 5, 2015