Possible bug importing source with inner interface

Don't know if the following is a known one, MPS version is 3.3-RC2 .

The case for me has been to create some code from an ecore model then import it as source stub.
The ecore model contains an enumeration an the generated code is in the form:

package test;

public enum PEElementCardinality implements InternalPEElementCardinality {

        OPTIONAL_VALUE, ARRAY, VALUE

}

interface InternalPEElementCardinality  {
}

When I tried to rebuild the solution I got this error message:

I don't know in which module's output path I should place class file for test.InternalPEElementCardinality

And the .class file is not generate for the interface:

marco@douglas /opt/working-dir/test-import-java $ find . -name *.class
./languages/NewLanguage/sandbox/classes_gen/test/PEElementCardinality.class
./languages/NewLanguage/generator/classes_gen/NewLanguage/generator/template/main/QueriesGenerated.class
./languages/NewLanguage/classes_gen/NewLanguage/Language.class

The solution was to put the interface declaration in its own file (I did it manually, don't know if ecore has a configuration for it).

See this project to replicate the problem:  test-import-java.tgz (12KB)

Bye,
Mar