Github user marevol commented on the issue:
https://github.com/apache/incubator-predictionio/pull/359
My environment is rpmbuild 4.12.0.1 in Ubuntu 16.04.
rpmbuild 5 seems to require rpmGroup.
Adding rpmGroup, I checked it on rpmbuild 4/5.
---
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.
---
