Drools maven plugin not understanding locally declared enums when compiling DRL files - maven

Question

I have been struggling with drools taking long to load rules on application startup. For this reason I have been looking at using the drools maven plugin to pre-compile my rules. However, while migrating my existing DRL files, I find that some of them do not compile.
This is happening where we have declared an enum in the DRL files and using it in the rule later on in the file. The error seems to happen because it does not understand the enum. i.e. unqualified type in strict mode for: SomeEnum
I have upgraded to the latest drools release (7.23.0) and simplified the example into the simplest use case I can think of.
I have a unit test that reads the DRL file in the test as a DRL Resource and executes the rule, and this test passes. But when I try to compile the rule itself, there are compilation issues.
Also, if I remove the enum and use a hardcoded value, the test passes in both cases.
My DRL file
declare enum SomeEnum
ENUM_KEY(1234L);
key: Long
end
rule "0_SomeRule"
dialect "mvel"
salience 3
when
response : Response ()
request : Request ()
then
response.key = SomeEnum.ENUM_KEY.getKey();
end
My kmodule file
<kmodule xmlns="http://www.drools.org/xsd/kmodule">
<kbase name="Test" packages="com.rawb.droolstest">
<ksession name="Test.session" type="stateless"/>
</kbase>
</kmodule>
The failing test:
public void testKJar() throws Exception {
KieServices ks = KieServices.Factory.get();
KieContainer kContainer = ks.getKieClasspathContainer();
StatelessKieSession kSession = kContainer.newStatelessKieSession("Test.session");
runRules(kSession);
}
private void runRules(StatelessKieSession kSession) {
List<Command> commands = new ArrayList<>();
commands.add(CommandFactory.newInsert(new Request(), "request"));
commands.add(CommandFactory.newInsert(new Response(), "response"));
commands.add(CommandFactory.newFireAllRules());
ExecutionResults executionResults = kSession.execute(CommandFactory.newBatchExecution(commands));
Response response = (Response) executionResults.getValue("response");
assertEquals(response.getKey(), 1234L);
}
The error message I recieve when running the test is as follows
[Error: unqualified type in strict mode for: SomeEnum]
[Near : {... response.key = SomeEnum.ENUM_KEY.getKey(); ....}]
^
[Line: 1, Column: 16]