time-limit
The next event is later than 10 minutes of simulated time.
A run ends when nothing is left to do, when it is stopped, or when the clock would pass 10 minutes of simulated time. Reaching that limit is an error, not a normal end, so a program that waits for something that never comes does not look like it succeeded. The error has no position, because no single line caused it.
Example
Run this program to see the diagnostic.
# package main
use std/sim
define main
after 601s
sim.StopAt 1s
Diagnostic
failed at 600s: error[time-limit]: the run reached 10 minutes of simulated time
Fix
Keep every delay within 10 minutes.
# package main
use std/sim
define main
after 60s
sim.StopAt 1s