I have been unable to work on this for a while but problem has not gone away.  I have an RCP that runs and Drools runs and works.  But when I try to run unit tests that involve Drools, I get this recurrent problem:

java.lang.NullPointerException

at org.mvel.optimizers.OptimizerFactory.<clinit>(OptimizerFactory.java:43)

at org.drools.rule.builder.dialect.mvel.MVELDialect.init(MVELDialect.java:142)

at org.drools.compiler.DialectRegistry.initAll(DialectRegistry.java:49)

at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:146)

at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:108)

at droolsRules.tests.AllDroolsRulesTests.setUp(AllDroolsRulesTests.java:48)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:585)

So I am writing to describe this environment again, and see if anyone has suggestions.

I have the Eclipse plugin in my development environment.  It is NOT in my target environment.

I have a privately minted "MinimalDroolsPlugin" that includes the core, compiler, and the dependency library.  THIS plugin is what is in my manifest.

This works when I run the application, as an RCP with product branding, or as a product.  When I use the target environment in Eclipse to create Mac, Linux, and W32 applications, all is well.

When I run JUnit tests, I get the error above.

I am wondering if the problem is the simultaneous presence of my minimal plugin as well as the eclipse Drools plugin?

The Drools jars that are needed by the application need to be incorporated into some kind of Eclipse plugin so that they are exposed, which is why I created the minimal plugin.  But if I leave this out completely and then try to setup a routine that imports a Drools compiler class, for example, Eclipse does not find it merely from the Eclipse plugins (Drools plugins).  

Sorry if this sounds ludicrous and confused, but any help greatly appreciated!

- Mike