The way the connector currently does it is that he adds a list of users to its cache with the help of the user_groups route. However, as seen in bug #9498, only some users (I assume administrators or some kind) can access that route. If a normal user uses the connector, he will get that error and won't be able to cache the list of users. I still need to confirm that this is the route of the problem, as Patricia seems to be able to get an error on this route, even though she's an admin (she doesn't have the current problem with the comment names though).

Also, when mapping the tuleap artifacts to the mylyn tasks, the user emails are used as an id to create an IRepositoryPerson and set it as author of the task comment. I changed it to use the username as the unique id of the person. This way, when fetching comments with the /artifacts/?id/changesets route, I can directly create a TuleapUser for the comment with the info I get from this route, as it already has the name, username and ldap_id of the person. I'll push the changes shortly on gerrit.

It seems to work if the logged in user has access to the /projects/?id/user_groups [GET] resource, as the connector uses this route to fill its usernames cache. I think this is a bit unnecessary as you can already get the comment submitter name when fetching /artifacts/?id/changesets with the fields:comments header. I'll see if I can get a workaround working.