Bug#958965: lost session with "Error: Cannot find master process to attach to!"

[Vincent Lefevre]

In the screen source, the error comes from attacher.c:

  for (;;)
    {
      signal(SIGALRM, AttacherSigAlarm);
      alarm(15);
      pause();
      alarm(0);
      if (kill(MasterPid, 0) < 0 && errno != EPERM)
        {
          debug1("attacher: Panic! MasterPid %d does not exist.\n", MasterPid);
          AttacherPanic++;
        }
      if (AttacherPanic)
        {
          fcntl(0, F_SETFL, 0);
          SetTTY(0, &attach_Mode);
          printf("\nError: Cannot find master process to attach to!\n");
          eexit(1);
        }

If I understand correctly, the kill() failed, probably because
the MasterPid process no longer existed. And I can confirm that
the SCREEN process was no longer running.

So, in short, the master process died. I don't know the reason,
but it did not leave a core dump. And it doesn't seem to have a
logging mechanism.

-- 
Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)