Using an external database for authentication, the task send_new_user_passwords_task fails: "$user->auth" is not setting.

Provisional solution:

At moodle_dir/lib/classes/task/send_new_user_passwords_task.php

Add "u.auth" field at line 55 (SQL)

$newusers = $DB->get_recordset_sql("SELECT u.id as id, u.email,
$usernamefields, u.username, u.lang,
p.id as prefid, u.auth
FROM {user} u
JOIN {user_preferences} p ON u.id=p.userid
WHERE p.name='create_password' AND p.value='1' AND
u.email !='' AND u.suspended = 0 AND
u.auth != 'nologin' AND u.deleted = 0");

Replication steps:

1) Make and poblate an external table for the authentication.

2) Configure Moodle for authentication via external database plugin.

3) Activate debbug messages.

4) Run the script: moodle_dir/auth/db/cli/sync_users.php (by command line or cron)

— All before is OK

5) Run the script: moodle_dir/lib/classes/task/send_new_user_passwords_task.php (FAIL)