As of version 40, addons such as GarrisonCommander that use setmetatable on tables returned by NewTable are breaking.

Thank you for raising this issue
GarrisonCommander is being updated for LibInit 40 (current beta) (same author sa LibInit, i.e. me :) )
I was not aware of anyone using LibInit but me, so I was maybe too much liberal in breaking backward compatibility.
Are you using it or you just downloaded it as a stand alone Library?

Ah, I'm not using it myself. I just like using standalone libraries so I have the "latest and greatest". Thanks for GarrisonCommander, btw :)

I see.
I updated both GarrisonCommander and OrderHallCommander to use LibInit 41

Fixed with release 41