I know this is old, but the client dont want to upgrade, but still want to monitor; the error when trying to install :
1 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Setting up sensu (0.26.5-2) …
groupadd: invalid option – r
Usage: groupadd [options] GROUP
-f, --force force exit with success status if the specified
group already exists
-g, --gid GID use GID for the new group
-h, --help display this help message and exit
-K, --key KEY=VALUE overrides /etc/login.defs defaults
-o, --non-unique allow create group with duplicate
dpkg: error processing sensu (–configure):
subprocess post-installation script returned error exit status 2
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)