[news.eclipse.newcomer] Strange NoClassDefFoundError

[Jochen <jochen.wuttke@xxxxxx>]

Hi,

I have a strange NoClassDefFoundError with my plugin.
The plugin loads fine with Eclipse, when I open the run configuration 
provided by the plugin I get the proper dialogs and everything, but when 
I try to "Run" the run-configuration I get the NoClassDefFoundError for 
the class that "Run" delegates to.
I'm a bit stumped by this, because obviously Eclipse finds some of the 
classes in my plugin, but not others.

Possibly relevant bits of my plugin.xml:

  <runtime>
      <library name="muclipse.jar">
         <export name="*"/>
      </library>
   </runtime>


     <extension
         point="org.eclipse.debug.core.launchConfigurationTypes">
      <launchConfigurationType

sourceLocatorId="org.eclipse.jdt.launching.sourceLocator.JavaSourceLookupDirector"
            delegate="edu.ncsu.muclipse.launch.MutantsLaunchConfigType"

sourcePathComputerId="org.eclipse.jdt.launching.sourceLookup.javaSourcePathComputer"
            name="MuClipse: Mutants"
            id="MuClipse.MutantsLaunchConfigType"
            modes="run,debug">
      </launchConfigurationType>
   </extension>

The JAR contains all the classes (it really does contain the class 
Eclipse complains about) and it finds the delegate for the 
LaunchConfigType without problems.
I've also tried to add the bin/ directory unpacked instead of as a JAR, 
but that did not change the behavior.

Is there some interference with different classloaders or am I missing 
something substantial here?

Thanks,
Jochen