Specifically, once a semester the lab systems would become the build nodes. The gfx/opengl class always used a textbook that was written around libvtk. Each new version had a new set of minimum versions for its long list of dependencies. This allowed for building the entire system to the same dependencies (vtk was very concerned with the version of libjpeg/pcx/etc whereas the rest of the system (eg x11, gnome) were happy with whatever vtk dictated.

Ccache only requires r/ssh access from the controller to any remote build nodes and the ccache program. I've never heard of anyone using this program as a shared cache source. That would be, well, kinda dumb. :/