Additional resources include Release Notes and Issue Tracker.
The source code for the library is hosted on Github at https://github.com/couchbase/libcouchbase.
The issue tracker for the library can be found at https://www.couchbase.com/issues/browse/CCBC. To file an issue, you must create an account with the issue tracker. After you create an account, file a new issue under the "Couchbase C Client Library" project.