A failed upgrade may lead to hung goroutines
Impact Processes using tableflip may encounter hung goroutines in the parent process, after a failed upgrade. The Go runtime has annoying behaviour around setting and clearing O_NONBLOCK: exec.Cmd.Start() ends up calling os.File.Fd() for any file in exec.Cmd.ExtraFiles. os.File.Fd() disables both the use of the runtime poller for the file and clears O_NONBLOCK from the underlying open file descriptor. This can lead to goroutines hanging in a parent process, after at …