Bug#794280: udev: Cannot upgrade: group 'input' already exists

Charles Plessy plessy at debian.org
Wed Apr 20 14:59:37 BST 2016

Le Tue, Aug 04, 2015 at 04:37:14PM +0200, Michael Biebl a écrit :
> Can you add a "set -x" to /var/lib/dpkg/info/udev.postinst to see at
> which point the postinst fails.

Hi Michael and everybody,

just for the record, I just stumbled on that bug on a virtual machine that I
administrate and ran the postinst script with "set -x":

Setting up udev (215-17+deb8u4) ...
+ case "$1" in
+ update_hwdb
+ udevadm hwdb --update --usr
+ addgroup --system input
addgroup: The group `input' already exists and is not a system group. Exiting.
dpkg: error processing package udev (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

It seems that the error is really caused by adduser...

I then circumvented the problme by deleting the "input" group and running
apt-get again, as suggested earlier in this thread.

Interesingly, I had a similar error with a systemd package and the
systemd-journal user.

Since the machine where I saw the problem has been installed by somebody else
than me, I can not exclude that the groups were added by hand, however I would
find this surprising.


Charles Plessy
Tsurumi, Kanagawa, Japan

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