How to upgrade Scala to a newer version from the command line?

Question

Is there away to upgrade the installed Scala version via sbt / other command line tool?

I'm sure there is a way, but I couldn't find any after a quick search, am I missing anything?

Answer 1

Each SBT project specifies the version of Scala to use to compile and run its code. It defaults to being the version of Scala that SBT uses internally, but is always overridable.

E.g.

  scalaVersion := "2.10.0"

As Connor Doyle mentioned, if your OS has a package system that includes Scala (some Linux distros I know of do) and you are, for some reason obligated to use that, you are pretty much at their mercy to provide a new version on a timely basis. The Scala Web Site (downloads here) provides a variety of installers and tarballs / Zip archives for every release they've made.

Mac OS X users can use HomeBrew to get up-to-date SBT and Scala.

Answer 2

To set the project version temporarily from the command line:

++ 2.10.4

To set the project version permanently from the command line:

set scalaVersion := "2.10.4"
session save