I haven't been able to follow this too closely, but I'm a little nervous that we should be changing some compiler setting rather than changing our code. In any case, if this ever worked in the past (and it did), it means the template definitions that are missing now are at least available to meas_algorithms (i.e. they're in headers, not buried in a .cc file), so the question is why meas_algorithms is no longer instantiating them.

If this does indeed do what we need to get the latest OS X working, then I don't have a problem with doing it, but we should open another fairly high-priority ticket to investigate this further and get to the bottom of it.

I agree. I'm especially worried that we needed to export SchemaImpl methods since those should only ever be called internally to Schema (if I understand). I'll clone this one to a Summer 2014 task.