Modify /usr/bin/libertine-xmir with an export TMPDIR=/tmp" before the exec line. 

Change the GU in the /etc/ubuntu-touch-session.d/[DEVICE].conf to a smaller value.

Testing from terminal the Xmir session can be started like this:
    $ Xmir :1 -mirSocket $XDG_RUNTIME_DIR/mir_socket --desktop_file_hint=dialer-app

the display need to be directed to the Xmir
    $ export DISPLAY=:1

Set the Qt Platform
    $ export QT_QPA_PLATFORM=xcb

Hack around the library path

# Qt Libs
    $ export LD_LIBRARY_PATH=/usr/lib/arm-linux-gnueabihf/:/opt/click.ubuntu.com/com.ubuntu.sdk/current/usr/ubuntu-sdk-ide/qtcreator/lib:/opt/click.ubuntu.com/com.ubuntu.sdk/current/usr/lib:$LD_LIBRARY_PATH
    $ export LD_LIBRARY_PATH=/opt/click.ubuntu.com/com.ubuntu.sdk/current/usr/ubuntu-sdk-dev/lib:$LD_LIBRARY_PATH



Set Qt Modules
    $ export QT_PLUGIN_PATH=/opt/click.ubuntu.com/com.ubuntu.sdk/current/usr/ubuntu-sdk-ide/bin/plugins/


Execute /opt/click.ubuntu.com/com.ubuntu.sdk/current/usr/ubuntu-sdk-ide/bin/qtcreator