Importing a custom accumulate function and a pojo from a different package the DRL compilation fails with the following message: "Error: Unknown accumulate function: 'myfunc' on rule 'test'. All accumulate functions must be registered before building a resource"
This is a one line fix, that comes with a regression test. It's extremely low risk and will be annoying to customers doing custom accumulate work, if it is not back ported.
Verified in BRMS 6.1.0 CR2.