Hi. We have this problem that we think may be an issue for others. We have a sitewide "helpdesk" role that does not have/want the "doanything" capability, and therefore appears in the group/members.php list - groups_get_users_not_in_group function in group/lib.php.

I'm fixing it temporarily with a new "local:course/participate" capability, for students, tutors and teachers. Do we want a "moodle:course/participate" or similar capability in core? (The OU may be able to implement this, but it probably won't be me - new job!)

(OU Bug 4469/ Sophie Gudgion, "helpdesk roles appear in group allocation listing")