[root@kolab ~]# rpm -qv guam
guam-0.7.3-4.1.el6.kolab_14.x86_64

The script: /etc/init.d/guam installed by this package is not setting the HOME variable. When using the "service" tool, the script attempt to start guam, but fails with:

[root@kolab ~]# service guam start
Starting guam
erlexec: HOME must be set
..........Unable to start
[root@kolab ~]#

Exporting the variable HOME in the script removes the error and guam is starting:

-----snip-----
start_cmd="$name start"
restart_cmd="$name restart"
stop_cmd="$name stop"
ping_cmd="$name ping"
user=""
export HOME="/root"

get_pid() {
    cat "$pid_file"
-----snip----