> I suspect this may be an issue now because the old svn approach was a
> full checkout for each build, whereas the hg approach is to pull to
> the local clone, and then just update the build tree.  So in the svn
> case all the files would have a good shot at the same timestamp,
> whereas with the hg approach the generated files get stale if the
> contents don't change.
> 
> I wonder if just doing a full checkout from the local clone would be
> closer to the old svn behavior in general with respect to timestamps
> and maybe a reasonable policy?

Ok, I've made the change on the DMG builders.