I hadn't seen anything posted to misc@ or tech@ about this yet, but wanted to thank the person responsible for the relatively recent addition (looks like late Oct or early Nov 2015) of the BUILDINFO file included with the kernel/base snapshots. I only noticed it last week and it was a rather nice surprise.
There's a tool I've cleverly dubbed 'trackcur' created and massaged over the years to help automate the process of following -current using the install kernel and binary packages. The original intent was to avoid some of the potential pitfalls I encountered while following the process manually (like updating to a flag-day snapshot which doesn't yet have package snapshots built or updating packages from a mirror still syncing from the master site), and it's grown to include other useful things to help stay up-to-date like syncing a repo via cvsync and checking out a local copy of src+ports from it. The biggest challenge was trying to devise a way to reliably and consistently track file timestamps on an arbitrary mirror via arbitrary transport without several hacky transport-specific methods -- e.g., HTML scraping and/or checking Last-Modified for HTTP transport. I'm not privy to how the snapshot package builds make it up to the master site, but would it be possible to generate a similar file that would live in the root of a given arch's package snaps? It would satisfy my selfish needs, but I think others may also see the value in a similar file for package builds. This would provide definitive information on the build, independent of file timestamps that may be lost or unavailable depending on the method of transfer. Is the generation of this file something that can be done relatively easy? Thanks, --avj