The Issue Tracking system for Coherence Incubator is hosted by java.net.
It can be found here: http://java.net/jira/browse/COHINC
To raise an issue representing a defect or feature request in the issue tracking system you need to have a java.net account. These are free. They don't require any personal information beyond that of an email address to confirm registration.
To resolve and close issues with the issue tracking system you will need to be a contributor.