The version of Blender packaged for Ubuntu 14.04 does not include the "WIREFRAME" modifier which is used by the new rendering engine. Requiring a more recent version of Blender is a "pain point". This can be worked around by either
a) using the older tracing engine with these versions of Blender, breaking consistency or
b) implementing a solid bounding-box generator in the code to avoid this dependency.
Closing for now; this is a lot of work, which will become redundant in subsequent OS versions. Documentation has been updated to reflect version requirement.
The version of Blender packaged for Ubuntu 14.04 does not include the "WIREFRAME" modifier which is used by the new rendering engine. Requiring a more recent version of Blender is a "pain point". This can be worked around by either
a) using the older tracing engine with these versions of Blender, breaking consistency or b) implementing a solid bounding-box generator in the code to avoid this dependency.