How to install an older version of scala

brew search scala

then you will find all the available versions like below

scala                     [email protected]                [email protected]                scalaenv                  scalariform               scalastyle
homebrew/science/scalapack                                                     Caskroom/cask/scala-ide

Then choose whichever version you want to install. say if you want to install scala 2.11 then you can do that by runnig the command like below

brew install [email protected]

If you manage your project with sbt, the scala built tool, either directly or via IntelliJ, the version of scala for that code is defined in the build file (build.sbt or Build.scala):

scalaVersion  := "2.10.5"

Choosing this path, there isn't even a need to install scala on your Mac at all. Each project will have its own version -- pulled from your local ivy repository, so it doesn't have to download it each time.

And rather than typing scala to get to the REPL, you type sbt console to get to the REPL with the project's scala version and dependencies loaded.

The following should work for Homebrew 0.9.5:

Install Tapped version of Scala 2.10

brew install homebrew/versions/scala210

Unlink version of Scala 2.11 (if installed)

brew unlink scala

Link Tapped version of Scala 2.10

brew link scala210 --force

Check scala version

scala -version