one window locked up, others accessible

[Abhijit Menon-Sen]

Hi.

I am running screen 4.00.02 on a Linux 2.6.20 machine that I'm ssh'ed in
to. I use screen -x to attach to a session with windows running programs
like mutt, lynx, etc. I sometimes encounter a problem that has lately
become annoyingly frequent.

With no apparent pattern, one of my screen windows will suddenly lock up
solid, as though I'd pressed ^AS (but I didn't, of course). I can switch
to other windows and use them normally, but I've never been able to coax
a window to come back to life from the frozen state. Killing it with ^AK
is the only option.

It happened again just now, and I ran strace on the screen process that
was the parent of the lynx I was using at the time (I was just pressing
the space bar to page through a long document). I noticed that screen
saw my keypress, and write a space to fd 7, which /proc/*/fd told me
was attached to /dev/ptmx. I separately straced the screen process,
but it didn't see any input at all.

This suggests that something went wrong with the connection between
screen and lynx, but I don't know what, or how to investigate further.

(Note: I have encountered this problem on a number of machines, with
different kernels, and very likely different versions of screen too.)

Has anyone else encountered this problem? Does anyone have suggestions
about how I can try to track it down? It's driving me nuts!

Thank you.

-- ams