$ DESKTOP_SESSION=unity8-mir MIR_SOCKET=$XDG_RUNTIME_DIR/mir_socket MIR_SERVER_PROMPT_FILE=1 MIR_SERVER_HOST_SOCKET=/run/lightdm-mir-0 MIR_SERVER_FILE=$XDG_RUNTIME_DIR/mir_socket MIR_SERVER_NAME=session-0 UNITY_INDICATOR_PROFILE=desktop QT_QPA_PLATFORM=mirserver  /usr/bin/unity8
[1423140239.106567] (II) SharedLibrary: Loading libmirplatform5driver.so
qtmir.mir: MirServer created

(unity8:4269): Gtk-WARNING **: cannot open display: