if one is building an image for a releasable, commercial product,
and that image involves pulling in numerous layers, then dumping all
sorts of proprietary apps on top of it, what are the possibilities for
how to version number the released images such that, if a client has
an issue, they can identify precisely the state of components that
went into the system they're working with?

  in addition to all of the layers involved in the build, one has to
take into account that, when critical bugs are identified, an updated
RPM might be sent out and applied, whereupon that system's version
number is no longer perfectly accurate. in the end, the state of
someone's running system will be determined by a possibly huge
combination of selected packages, preferred package versions, build
config options, additional user space apps, hot fixes that have been
applied and so on.

  what sort of meaningful "version number" can be applied to something
like that? i'm sure at least a few other people have to be doing
something like that, so i'm open to suggestions.