Step "Tails Greeter has applied all settings" is fragile

The test suite sometimes fails after clicking on the login button of the Greeter. The next loginctl test to see if the X session is opened can’t find one apart the Gdm one.

It happened:

• 3 times so far in July
• 6 times in June
• 18 in May
• 5 in April
• 13 in March
• 12 in February
• 13 in January

But all this failures might not be due to the same reasons.

Maybe we need to raise a bit the waiting time for the session to open. Or there’s a bug in the Tails X session opening, or that’s #11816 (closed) having being closed a bit too fast. This needs investigation.

Feature Branch: https://salsa.debian.org/tails-team/tails/merge_requests/33

Parent Task: #10288

Related issues

• Related to #12289 (closed)
• Related to #11816 (closed)

Original created by @bertagaz on 13470 (Redmine)