Install PHP Extension for PHP 5.6 on OSX with deprecated homebrew/php

First install exolnet/homebrew-deprecated

$ brew tap exolnet/homebrew-deprecated

After it install deprecated package

$ brew install php@5.6

I've found a solution to use old version of homebrew/php on my Mac.

Step 1

Go to last valid release of homebrew/php for php56

https://github.com/Homebrew/homebrew-php/tree/966f6c318be2d80b4953cd8cdc112b9611eff8d9

and download the Zip file.

homebrew-php-966f6c318be2d80b4953cd8cdc112b9611eff8d9.zip

Step 2

Go to

/usr/local/Homebrew/Library/Taps/homebrew/

and rename the Tap

homebrew-php

in

old-homebrew-php

Step 3

Unzip

homebrew-php-966f6c318be2d80b4953cd8cdc112b9611eff8d9.zip

in

/usr/local/Homebrew/Library/Taps/homebrew/ 

and rename folder in

homebrew-php

Step 4

Search your php extension with brew:

$ brew search php56-redis==> Searching local taps...homebrew/php/php56-redis==> Searching taps on GitHub...==> Searching blacklisted, migrated and deleted formulae...

Step 5

Install pakages without updates:

HOMEBREW_NO_AUTO_UPDATE=1 brew install homebrew/php/<formula>

This will stop the homebrew update for this command. If you want to prevent auto update for your shell session, use:

export HOMEBREW_NO_AUTO_UPDATE=1

to set it permanently, add it to your ~/.bash_profile.