Github user StephanEwen commented on the issue:
https://github.com/apache/flink/pull/2305
I think it breaks binary compatibility, not source compatibility.
The specific return type is part of the method signature used by the JVM
for linking.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
