obsup: hack extension to make in-place upgrading of obsolete markers easy I tried upgrading my obsstore by doing a local clone as suggested by Pierre-Yves and Sean, but that caused me to end up with a ton of unstable changes that should have been marked dead. In fact, as far as I can tell, most of the performance win of that upgrade came from the fact that only about 46% (46672 of 102285) of my markers were brought over with the copy-and-pull method.