When live upgrading from Mesos 0.22.x to 0.23.x the old running mesos-0.22.x slaves call out to the newly instaleld 0.23.x fetcher and fails with:
F0914 11:43:16.355821 28833 fetcher.cpp:415] CHECK_SOME(fetcherInfo): Missing required fields: sandbox_directory Failed to parse FetcherInfo: Missing required fields: sandbox_directory
This is because the old 0.22.x slave does not include those fields apparently, that the 0.23.x fetcher requires.
Here's another report of that happening: http://wilderness.apache.org/channels/?f=mesos/2015-07-29
Just wanted to raise to attention that this makes it annoying to live upgrade from 0.22.x to 0.23.x which otherwise would be smooth.