When harvesting a CKAN instance (source install v2.5.0a as of July 2015) into another CKAN instance (datacats using latest master, v2.5.0a) with a custom ckanext-scheming dataset schema, I'm running into DetachedInstanceError indicating that the db conection via SQLAlchemy changes sessions.

DetachedInstanceError('Instance <User at 0x7fdf11ae5e50> is not bound to a Session; attribute refresh operation cannot proceed',)

My config:

{
 "api_version": 1,
 "user": "harvest",
 "remote_groups": "create",
 "remote_orgs": "create",
 "override_extras": true,
 "read_only": true,
 "force_all": true
}

I've created a sysadmin user called "harvest", same error as with my own sysadmin account.

I haven't seen a DetachedInstanceError since mentioned in the dev meeting archives a year ago.
Has anyone seen this error lately, or is harvesting only broken on my end?