I have a few kegs of the same package in /usr/local/Cellar/libfoo like /usr/local/Cellar/libfoo/1.0.1, /usr/local/Cellar/libfoo/HEAD and /usr/local/Cellar/libfoo/mycopy
How can I brew link to a specific version?
I have a few kegs of the same package in /usr/local/Cellar/libfoo like /usr/local/Cellar/libfoo/1.0.1, /usr/local/Cellar/libfoo/HEAD and /usr/local/Cellar/libfoo/mycopy
How can I brew link to a specific version?
 
    
     
    
    This is probably the best way as of 11.1.2022:
To install a specific version, e.g. postgresql 9.5 you simply run:
$ brew install postgresql@9.5
To list the available versions run a search with @:
$ brew search postgresql@
==> Formulae
postgresql                 postgresql@11              postgresql@13              postgresql@9.5             qt-postgresql
postgresql@10              postgresql@12              postgresql@9.4             postgresql@9.6             postgrest
==> Casks
navicat-for-postgresql
DEPRECATED in Homebrew 2.6.0 (December 2020):
The usage info:
Usage: brew switch <formula> <version>
Example:
brew switch mysql 5.5.29
You can find the versions installed on your system with info.
brew info mysql
And to see the available versions to install, you can provide a dud version number, as brew will helpfully respond with the available version numbers:
brew switch mysql 0
Update (15.10.2014):
The brew versions command has been removed from brew, but, if you do wish to use this command first run brew tap homebrew/boneyard.
The recommended way to install an old version is to install from the homebrew/versions repo as follows:
$ brew tap homebrew/versions
$ brew install mysql55
For detailed info on all the ways to install an older version of a formula read this answer.
Sadly brew switch is deprecated in Homebrew 2.6.0 (December 2020)
$ brew switch
Error: Unknown command: switch
TLDR, to switch to package version 10:
brew unlink package
brew link package@10
To use another version of a package, for example node:
brew list. My package here is node (16) and node@14.➜  ~ brew list
==> Formulae
node
node@14
➜  ~ node -v
v16.1.0
brew unlink node.➜  ~ brew unlink node
Unlinking /usr/local/Cellar/node/16.1.0... 7 symlinks removed.
➜  ~ brew link node@14
Linking /usr/local/Cellar/node@14/14.16.1_1... 3857 symlinks created.
If you need to have this software first in your PATH instead consider running:
  echo 'export PATH="/usr/local/opt/node@14/bin:$PATH"' >> ~/.zshrc
➜  ~ node -v
v14.16.1
 
    
    Homebrew removed brew switch subcommand in Homebrew 2.6.0. Get it back from here.
brew tap laggardkernel/tap
brew switch --help
There's mainly two ways to switch to an old version of an app.
If it's a bigger version change. Homebrew may have created a versioned package in the repo. Like go, go@1.10, they are two different formulae, installed into two different locations.
# install the old one
brew install go@1.10
# link the executable into /usr/local/bin, or /opt/homebrew/bin
brew link --overwrite --force go@1.10
But not every package has a versioned variant. If you just upgraded to the new version and the old one is still in your system, skip step 1, 2.
brew install /path/to/downloaded/mysql.rb.mysql) exist, switch (link out) the old version with brew switch mysql 8.0.23brew info mysql will list all the old version still exist.
Step 1, 2 could be replaced by brew extract, but that requires user maintain its own tap. I won't cover it here, just search it if you're interested.
 
    
    If you have installed, for example, php 5.4 it could be switched in the following way to php 5.5:
$ php --version
PHP 5.4.32 (cli) (built: Aug 26 2014 15:14:01) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies
$ brew unlink php54
$ brew switch php55 5.5.16
$ php --version
PHP 5.5.16 (cli) (built: Sep  9 2014 14:27:18) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
 
    
    brew switch libfoo mycopy
You can use brew switch to switch between versions of the same package, if it's installed as versioned subdirectories under Cellar/<packagename>/
This will list versions installed ( for example I had Cellar/sdl2/2.0.3, I've compiled into Cellar/sdl2/2.0.4)
brew info sdl2
Then to switch between them
brew switch sdl2 2.0.4
brew info 
Info now shows * next to the 2.0.4
To install under Cellar/<packagename>/<version> from source you can do for example
cd ~/somewhere/src/foo-2.0.4
./configure --prefix $(brew --Cellar)/foo/2.0.4
make
check where it gets installed with
make install -n
if all looks correct
make install
Then from cd $(brew --Cellar) do the switch between version.
I'm using brew version 0.9.5
 
    
    In case brew switch produces an error (in this example trying to switch to node version 14):
> brew switch node 14
Error: Calling `brew switch` is disabled! Use `brew link` @-versioned formulae instead.
The correct way switching versions would be :
> brew link --overwrite node@14
 
    
    if @simon's answer is not working in some of the mac's please follow the below process.
If you have already installed swiftgen using the following commands:
$ brew update
$ brew install swiftgen
then follow the steps below in order to run swiftgen with older version.
Step 1: brew uninstall swiftgen
Step 2: Navigate to: https://github.com/SwiftGen/SwiftGen/releases
and download the swiftgen with version: swiftgen-4.2.0.zip.
Unzip the package in any of the directories.
Step 3: Execute the following in a terminal:
$ mkdir -p ~/dependencies/swiftgen
$ cp -R ~/<your_directory_name>/swiftgen-4.2.0/ ~/dependencies/swiftgen
$ cd /usr/local/bin
$ ln -s ~/dependencies/swiftgen/bin/swiftgen swiftgen
$ mkdir ~/Library/Application\ Support/SwiftGen
$ ln -s ~/dependencies/swiftgen/templates/ ~/Library/Application\ Support/SwiftGen/
$ swiftgen --version
You should get: SwiftGen v0.0 (Stencil v0.8.0, StencilSwiftKit v1.0.0, SwiftGenKit v1.0.1)
