Comparing to GNU/Linux, on GNU/Hurd it happens much more often and easily for screen sessions to become dead. This is annoying, as it defeats one of screen's main purposes.

One reproducible scenario goes like this

• ssh [somewhere],

• start a screen session, and some long-running process P in there,

• at some point the link is forcefully terminated (also known as disconnect after 24 hours with consumer DSL),

• P will continue to execute,

• at some point, P will terminate / hang (after having received some kind of signal?), and the screen session will be reported as dead.

Another one, not as often reproduced

• ssh [somewhere],

• start a screen session, and some long-running process P in there,

• at some point the link is forcefully terminated (also known as disconnect after 24 hours with consumer DSL),

• ssh [somewhere],

• screen -x, and notice that P will immediatelly terminate / hang (after having received some kind of signal?), and the screen session will immediatelly be reported as dead. (Perhaps the other way round: upon re-attaching, the screen session goes bonkers and takes P with it?)

IRC, freenode, #hurd, 2011-10-19

<antrik> tschwinge: hm... haven't seen screen dying in a long time
<tschwinge> antrik: It's easy, and goes like this: have a session on one
  system, log in from another, do screen -x and wait some time.
<antrik> I do this regularily. haven't had a crash in ages.
<antrik> (BTW, I'm not sure I ever had a crash on srceen -x... at that
  time, I wasn't using -x. I often had crashes with screen -r. my
  impression back then was that it works better when doing -rd -- in fact,
  I always do that now, so I can't say whether crashes still happen with
  only -r...)

2011-10-26:

<antrik> so I was saying the other day that I haven't had a screen crash in
  a long time... well, here it was :-(
<antrik> this time it didn't crash on reconnect though, but already
  before. probably when I killed the hanging ssh connection