How do I render a bone or an armature?
I think your only option is to use the “OpenGL Render” buttons in the 3D view header (the camera and clapper board icons).
If you want to go through the trouble, you’d have to actually model the bones as meshes and match the beginning and end points and assing them to the bone with 100% weight each.
Failed to create OpenGL offscreen buffer: Unknown
Maybe parenting the endpoints?
there was an add-on on blendernation some weeks ago which converts bones to wireframe meshes. the intention of the add-on is to generate custom bone shapes for controller bones. thus, the add-on converts each bone to a mesh object which can be edited to the desired shape.
I think you can (mis)use it for your needs. unfortunately I don’t remember its name but you should find it on the interweb.