homebrew - how to install older versions

Usually, you can check if multiple versions are available and you can specify the version with @. e.g. brew install [email protected]

$ brew info memcached

memcached: stable 1.4.24
High performance, distributed memory object caching system
https://memcached.org/
Conflicts with:
  mysql-cluster (because both install `bin/memcached`)
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/memcached.rb
...

If is not available the version you want you can go to the repo, and check the history

cd "$(brew --repo homebrew/core)"
git log master -- Formula/memcached.rb

Then you can find the commit you are looking for

commit 5ec463decefeaab3d1825b923ad2dbee73ffc6dc
Author: Adam Vandenberg <[email protected]>
Date:   Fri Apr 9 21:19:48 2010 -0700

    Update memcached to 1.4.5

Checkout that version and install:

cd "$(brew --repo homebrew/core)" && git checkout 5ec463decefeaab3d1825b923ad2dbee73ffc6dc
HOMEBREW_NO_AUTO_UPDATE=1 brew install memcached

Once you get the version installed, you can bring brew to its latest version with:

git checkout master

and, that's it!

I would do

brew unlink memecached
brew install [email protected]
brew link [email protected] --force

A more expanded version of the good answer from Adrian is also here on SO.

https://stackoverflow.com/a/53766019/3794873

One thing to keep in mind is that if you are installing an older Formula the Homebrew API/methods may have changed since that time so you should brew edit appFormula against the current version and compare to the brew edit [email protected] if you encounter any errors trying to brew install [email protected] after the brew extract command in the answer linked.