NoClassDefFoundError...org/apache/commons/cli/CommandLineParser when Run As, Groovy Script

Question

I just installed Eclipse KEPLER and am trying to bring all my projects back in from github. The projects are all gradle projects so my procedure is pretty much...

1. Clone the git repo
2. gradle eclipse
3. Import Project into Eclipse

Everything seems to be fine, except I can't "Run As, Groovy Script" the scripts within the project. When I try, the console spews...

java.lang.NoClassDefFoundError: org/apache/commons/cli/CommandLineParser
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2521)
    at java.lang.Class.getMethod0(Class.java:2764)
    at java.lang.Class.getMethod(Class.java:1653)
    at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:99)
    at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:130)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.cli.CommandLineParser
    at org.codehaus.groovy.tools.RootLoader.findClass(RootLoader.java:156)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at org.codehaus.groovy.tools.RootLoader.loadClass(RootLoader.java:128)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 6 more

. Interestingly enough, I can "Run As, Java Application" without issue. Its definitely a Groovy project as it has the G in the project icon. What does the stacktrace mean and how do I overcome it?

The repository that is causing my issue is at https://github.com/robertkuhar/StackOverflow

My gradle is 1.11 on groovy 1.8.6 in eclipse kepler with the Groovy-Eclipse plug-in Version: 2.8.0.xx-20130703-1600-e43-RELEASE

Answer 1

Looks like when creating the "Groovy Script" run configuration, the main class is set to org.codehaus.groovy.tools.GroovyStarter instead of the script you are intending to run. Replacing it with the Groovy class/script you would like to run sorts the issue.

Update

After some digging the way to solve the issue is:

• Remove the Groovy dependency from the Gradle build.
• Configure the project classpath and nature, as suggested in this answer

build.gradle

eclipse {
    project {
        natures.add 'org.eclipse.jdt.groovy.core.groovyNature'
    }
    classpath {
        file {
            withXml {
                Node node = it.asNode()
                node.appendNode('classpathentry',[exported:"true",kind:"con",path:"GROOVY_SUPPORT"]) 
                node.appendNode('classpathentry',[exported:"true",kind:"con",path:"GROOVY_DSL_SUPPORT"])
            }
        }
    }
}