The 5ms ServiceBannerRefreshInterval caused excessive DRPC
connection churn (200 calls/s) under the race detector, creating
heavy mutex contention on FakeAgentAPI and significant CPU overhead.
This made the test timing-sensitive in ways that manifested as
session.Wait() hangs, killing the test binary via timeout.
Three changes:
- Increase refresh interval from 5ms to testutil.IntervalFast (25ms),
reducing DRPC connection churn and mutex contention by 5x.
- Replace bare <-ready receives with testutil.TryReceive so the test
fails with context expiry instead of hanging indefinitely.
- Add a timeout to session.Wait() in testSessionOutput to prevent any
SSH session hang from killing the entire test binary.
Fixescoder/internal#1417
Mathias Fredriksson
c60a3568d7