Installing Groovy 1.8: NoClassDefFoundError: GroovyStarter

Today, I tried installing Groovy 1.8-rc-3 so I could play with some of the new features of the language. On my Ubuntu machine, the current version I had installed from the repositories was 1.7.6, which in itself is pretty recent:

  $ groovy --version
  Groovy Version: 1.7.6 JVM: 1.6.0_13

Since I installed Groovy through the Ubunutu repositories using apt-get, the groovy executable was already on my path:

  $ which groovy
  /usr/bin/groovy

As I did not want to mess with the default install, to get 1.8 into the picture, I would have to install things manually. After unzipping the install, I expected to be able to run it easily, but I ran into an exception:

  $ /opt/groovy-1.8.0-rc-3/bin/groovy --version
   Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/groovy/tools/GroovyStarter
   Caused by: java.lang.ClassNotFoundException: org.codehaus.groovy.tools.GroovyStarter
           at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
           ...
   Could not find the main class: org.codehaus.groovy.tools.GroovyStarter.  Program will exit.

Of course by instinct, I went to Google, but before I went to far, it hit me to check GROOVY_HOME:

  $ echo $GROOVY_HOME
  /usr/share/groovy

After changing the value to my new install, I was able to verify the install:

  $ export $GROOVY_HOME='/opt/groovy-1.8.0-rc-3'
  $ /opt/groovy-1.8.0-rc-3/bin/groovy --version
  Groovy Version: 1.8.0-rc-3 JVM: 1.6.0_13

Nothing groundbreaking here, but hopefully I won't forget about this the next time and jump to a search page.