From the mailing list:
is it possible for the console message
found shader 'mitkShaderLighting'
ie: https://github.com/MITK/MITK/blob/master/Core/Code/Rendering/mitkShaderRepository.cpp#L69
to be removed from the default output. It causes command line apps to print this first, and then the --xml flag fails to parse.
It could be a debug only message maybe.