installing sbt-assembly with sbt 0.11.2

Question

I am trying to install sbt-assembly by following the instructions in order to make a stand-alone jar that can run on a computer without scala installed.

So far these are the steps I've taken.

I created a plugins.sbt file:

$ cat sbt/project/plugins.sbt 
addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.7.2")

And I added the following to the beginning of my build.sbt file:

$ head -n3 sbt/build.sbt 
import AssemblyKeys._ // put this at the top of the file

seq(assemblySettings: _*)

But when I run sbt, I get the following error:

sbt/build.sbt:1: error: not found: value AssemblyKeys
import AssemblyKeys._ 

Answer 1

1. Make sure you are running sbt version at least 0.11 by typing

   $ sbt sbt-version

   at the bash prompt.

2. Make sure you have the plugins file set up as follows:

   $ cat sbt/project/plugins.sbt
   
   addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.7.2")
   

3. Make your build file (build.sbt) look like this:

   import AssemblyKeys._ 
   
   seq(assemblySettings: _*)
   
   name := "my_project"
   
   version := "1.0"
   
   scalaVersion := "2.9.1"
   
   libraryDependencies ++= Seq(
     "org.scalatest" %% "scalatest" % "1.6.1" % "test",
     "commons-lang" % "commons-lang" % "2.6"
   )
   
   traceLevel in run := 0
   
   fork in run := true
   
   scalacOptions ++= Seq("-optimize")
   
   // The following is the class that will run when the jar is compiled!
   
   mainClass in assembly := Some("MyMain")
   

Answer 2

Make sure you don't have a project/plugins folder lying around. This may prevent other mechanisms of specifying plugins from working.