Comment 6 for bug 1332126

... and HOME. If I do:

env -i PATH=... USER=maeder LANG=... HOME=... /usr/bin/nice -n 19 ...

the error does pop up. The output contains:

WARNING: import keyring failed
backintime(5806)/kdeui (kdelibs): Session bus not found
To circumvent this problem try the following command (with Linux and bash)
export $(dbus-launch)
KCrash: Application 'kde4systrayicon.py' crashing...
KCrash: Attempting to start /usr/lib/kde4/libexec/drkonqi from kdeinit
sock_file=/home/maeder/.kde/socket-madbox/kdeinit4__0
Unable to start Dr. Konqi
Re-raising signal for Apport handling.

after which the rsync is done successfully.

If I add DBUS_SESSION_BUS_ADDRESS, DBUS_SESSION_BUS_PID and DBUS_SESSION_BUS_WINDOWID to the mix (according to the output of echo $(dbus-launch)), everything runs smoothly:

env -i PATH=... USER=maeder LANG=... HOME=... DBUS_SESSION_BUS_ADDRESS=... DBUS_SESSION_BUS_PID=... DBUS_SESSION_BUS_WINDOWID=... /usr/bin/nice -n 19 /usr/bin/ionice -c2 -n7 /usr/bin/backintime --backup-job

INFO: Lock
INFO: mount local_encfs: ... on /tmp/backintime/maeder/mnt/31B6C79F/mountpoint
INFO: on process begins
INFO: Profile_id: 1
INFO: Call rsync to take the snapshot
etc.