Your message dated Wed, 20 May 2026 16:56:40 +0200
with message-id <[email protected]>
and subject line Cannot reproduce on a modern screen
has caused the Debian Bug report #502360,
regarding Race conditions with 'screen -X cmd' and 'screen cmd' cause logging
to file to fail
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
502360: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502360
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: screen
Version: 4.0.3-0.3
Severity: normal
At work, we automate things with screen, invoked from shell scripts. Among
other things, the scripts create new, named windows and turn on logging for
them. This broke when we upgraded from 4.0.2 to screen 4.0.3.
(Actually, we run RedHat Enterprise Linux, but the problem is repeatable with
Debian. Either upstream 4.0.3 did this, or RH and Debian include the same
bad patch.)
The symptom is that if you create windows too fast (by calling the screen
binary)
and send commands too fast (by calling screen -X cmd) some of them will fail.
It's easy to see if you start a screen and run this shell script:
------------------------------
#!/bin/sh
[ -z "$STY" ] && {
echo "no screen"
exit 1
}
mkdir -p /tmp/qgrajor || exit 1
for name in $(seq 1 5) ; do
name="screen_$name"
screen -t "$name" sort
# sleep 1 # enabling this delay "fixes" the problem
screen -p "$name" -X logfile "/tmp/bug-$name"
screen -p "$name" -X log on
done
------------------------------
What typically happens is that screen_5 doesn't get logging enabled,
but other problems may happen too (other windows not having logging,
maybe also windows not opening).
I feel this is a serious regression because it prevents automation. I can add
a delay like the one commented out above, but I have no idea if one second
is always sufficient. It's not a good workaround.
regards,
Jorgen
-- System Information:
Debian Release: 4.0
APT prefers stable
APT policy: (500, 'stable')
Architecture: powerpc (ppc)
Shell: /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-3-powerpc
Locale: LANG=sv_SE.utf8, LC_CTYPE=sv_SE.utf8 (charmap=UTF-8)
Versions of packages screen depends on:
ii base-passwd 3.5.11 Debian base system master password
ii debconf [debconf-2.0] 1.5.11etch2 Debian configuration management sy
ii libc6 2.3.6.ds1-13etch7 GNU C Library: Shared libraries
ii libncursesw5 5.5-5 Shared libraries for terminal hand
ii libpam0g 0.79-5 Pluggable Authentication Modules l
ii passwd 1:4.0.18.1-7 change and administer password and
screen recommends no packages.
-- debconf information:
screen/old_upgrade_prompt: false
--- End Message ---
--- Begin Message ---
Version: 4.9.0-4
Hi,
I've tried to reproduce this using the supplied script, even up to 20
sessions with no sleep delay. I get 20 windows with 20 log files.
I can't reproduce this on a modern screen version (either 4.9.0-4 or
5.0.1-2).
I presume this was fixed a long time ago, but marking as fixed in the
oldest version I tested.
Cheers,
Peter
--- End Message ---
