java.lang.IllegalArgumentException: startPos = -1 and length is 2.
This breaks the rule that length must be 0 if startPosition is negative. Affected Node:
{
}

at lombok.eclipse.agent.PatchDiagnostics.setSourceRangeCheck(PatchDiagnostics.java:38)(this is the same as the next basically just a wrapper)
at org.eclipse.jdt.core.dom.ASTNode.setSourceRange(ASTNode.java)
at org.eclipse.jdt.core.dom.ASTConverter.convert(ASTConverter.java:2516)
I have generated a fair bit of code but until this point there was no need for me to set positions. So my guess is that I'm missing something that is not related to source or body end/start pos.

java.lang.Runnable generated = new java.lang.Runnable() {
      public void run() {
      }
};

void handle( Annotation ast, EclipseNode annotationNode) {
        EclipseNode parentClass = annotationNode.up();  
        LocalDeclaration runnableField = new LocalDeclaration("generated".toCharArray(), 0, 0);
        runnableField.modifiers = 0;
        runnableField.type = createQualifiedTypeReference("java.lang.Runnable");
        runnableField.initialization = createNewRunnableImplementation(parentClass,ast);    
        //.. here I create a method and add this local decl to its statement,
        // I don't think the problem is here so I do not include it
    }
private Expression createNewRunnableImplementation(EclipseNode classNode, Annotation source) {
     MethodDeclaration runMethod = new MethodDeclaration(((TypeDeclaration)(classNode.get())).compilationResult);
     runMethod.modifiers = Modifier.PUBLIC;
     runMethod.returnType = new SingleTypeReference(TypeConstants.VOID, 0);
     runMethod.selector = "run".toCharArray();


     TypeDeclaration newRunnableType = new TypeDeclaration(((TypeDeclaration)(classNode.get())).compilationResult);
     newRunnableType.modifiers = 0;
     newRunnableType.name = CharOperation.NO_CHAR;
     newRunnableType.methods = new AbstractMethodDeclaration[] {runMethod};
     newRunnableType.bits = ASTNode.IsAnonymousType;

     QualifiedAllocationExpression runnableInit = new QualifiedAllocationExpression(newRunnableType);
     runnableInit.type = createQualifiedTypeReference("java.lang.Runnable");
     return runnableInit;
}