laney@yakkety-vm:/usr/lib/systemd/user$ journalctl --user-unit=im-config | grep XMODIFIERS
Oct 04 09:49:19 yakkety-vm sh[1939]: XMODIFIERS=@im=ibus
Oct 04 09:49:19 yakkety-vm sh[1939]: + dbus-update-activation-environment --verbose --systemd XMODIFIERS
Oct 04 09:49:19 yakkety-vm sh[1939]: dbus-update-activation-environment: setting XMODIFIERS=@im=ibus
Oct 04 09:49:19 yakkety-vm sh[1939]: + eval echo $XMODIFIERS
Oct 04 09:49:19 yakkety-vm sh[1939]: + initctl set-env -gr XMODIFIERS=@im=ibus
laney@yakkety-vm:/usr/lib/systemd/user$ strings /proc/$(pidof compiz)/environ | grep XMODIFIERS
XMODIFIERS=@im