When a jira role is attached to a group, the converter doesn't distinguish with a user and then try to find as a user and fail. At the end people are not imported.

Import mechanism should flatten the group membership to only import users.

[debug] GET /rest/api/2/project/JIRACODE/role
[debug] User with account id Administrators is unknown, querying /rest/api/2/user?key=Administrators ...
[warning] Impossible to get user Administrators: Query `GET https://jira.example.com/rest/api/2/user?key=Administrators` was not successful (code: 404, message: "Not Found"). Jira errors:
The user with the key 'Administrators' does not exist
Jira warnings:
. Fallback to default user