The CDS oscillator part doesn't work inside subsystems.
Rolf checked in an older version of the CDS oscillator which includes an input (which you just connect to a ground). This makes the parser work properly so you can build with the oscillator in a subsystem.
So I did an SVN checkout and confirmed that the custom changes we have here were not overwritten.
Turns out the latest svn version requires new locations for certain codes, such as EPICS installs. I reverted back to version 2160, which is just before the new EPICs and other rtapps directory locations, but late enough to pick up the temporary fix to the CDS oscillator part.