Unable to import users from Jira

I'm using Crowd 2.8 to import users from our legacy Jira system into a Crowd internal directory. The users and groups from Jira are migrated, but the group memberships do not (i.e. the groups in Crowd are empty). In Crowd's catalina.out I see:

2015-05-13 15:49:56,244 http-bio-8095-exec-4 INFO [crowd.importer.importers.BaseImporter] Importing 1019 users.
2015-05-13 15:50:02,856 http-bio-8095-exec-4 INFO [crowd.importer.importers.BaseImporter] Importing user-to-group member
ships.
2015-05-13 15:50:02,862 http-bio-8095-exec-4 ERROR [crowd.importer.importers.BaseImporter] Could not add memberships for
group 'disaster-planning-committee' as it does not exist in directory with ID: 4096002
com.atlassian.crowd.exception.GroupNotFoundException: Group <disaster-planning-committee> does not exist
at com.atlassian.crowd.dao.group.GroupDAOHibernate.findByName(GroupDAOHibernate.java:158)
at com.atlassian.crowd.dao.group.GroupDAOHibernate.findByName(GroupDAOHibernate.java:46)
at com.atlassian.crowd.directory.AbstractInternalDirectory.findGroupByName(AbstractInternalDirectory.java:783)
at com.atlassian.crowd.directory.AbstractInternalDirectory.findGroupByName(AbstractInternalDirectory.java:64)
at com.atlassian.crowd.manager.directory.DirectoryManagerGeneric.findGroupByName(DirectoryManagerGeneric.java:48
4)
at com.atlassian.crowd.manager.directory.DirectoryManagerGeneric.addAllUsersToGroup(DirectoryManagerGeneric.java
:1323)

....

I see a "Could not add memberships for group ..." line for (presumably) every group we've imported.

Of course, at the end of the import process, I would expect to have all the users and groups and their memberships represented in the Crowd directory.

Many thanks for allowing us to directly create bugs in your system!