optirun Bumblebee Linux: VLC only runs with CLI interface

[gryphonB]

Hi,
I have Kubuntu 14 on a laptop with a hybrid GPU: an integrated low power Intel plus a more powerful discrete nVidia. I just installed Bumblebee, the current Linux method for running both GPUs.
I'd like to run VLC through the nVidia GPU thusly:

Code: Select all

optirun|primusrun vlc

This brings up the VLC command line interface, instead of the normal window
If I specify a file, vlc runs it beautifully, without the usual tearing & much lighter on resources.
Other apps work fine: Firefox, Gwenview, mpv
VLC writes these messages:
> primusrun vlc &
[1] 23290
g@Slice:
VLC media player 2.2.1 Terry Pratchett (Weatherwax) (revision 2.2.1~trusty1)
[0000000000f76118] core libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
../../../include/vlc_xlib.h:46:vlc_xlib_init: Xlib not initialized for threads.
This process is probably using LibVLC incorrectly.
Pass "--no-xlib" to libvlc_new() to fix this.
[0000000000fa1e08] qt4 interface error: Xlib not initialized for threads
../../../include/vlc_xlib.h:46:vlc_xlib_init: Xlib not initialized for threads.
This process is probably using LibVLC incorrectly.
Pass "--no-xlib" to libvlc_new() to fix this.
[0000000000fa1e08] skins2 interface error: Xlib not initialized for threads
[0000000000fa1e08] skins2 interface error: initializing xlib for multi-threading failed
[0000000000fa1e08] skins2 interface error: cannot initialize OSFactory
[0000000000fa1e08] [cli] lua interface: Listening on host "*console".
VLC media player 2.2.1 Terry Pratchett (Weatherwax)
Command Line Interface initialized. Type `help' for help.
>

[gryphonB]

(Continued)
Previously when I had Bumblebee installed, VLC worked well with it.
I also tried passing the "--no-xlib" option - same result.
Is there a simple fix to enable VLC on the nVidia GPU?