View source for Yocto sstate usage summary to the build

== Yocto usage Sstate summary to the build ==

When building in Yocto Project the user has indication of how much sstate was already present
or that would be used by the build thanks to the '''Sstate summary''' message.

 Sstate summary: Wanted 11 Found 11 Missed 0 Current 188 (100% match, 100% complete)



'''Wanted''' is the number of artefacts the build ideally wants from sstate

'''Found''' is the number of artefacts present in sstate locally or it thinks
are fetchable from any mirrors

'''Missed''' = Wanted - Found

'''Current''' is the number of stamps which bitbake viewed as "current", i.e.
it needed to do nothing. Since they're current, it wouldn't bother
querying sstate or considering them any further.

'''"% match"''' tells you how much of the sstate queried, matched

'''"% complete"''' tells you how much of the build is already current or
completed

The reason the current/complete numbers are there are because a build
directory where a build has already partly completed could show a "0%
match" against sstate but its not immediately clear that things which
have already run are never checked for in sstate. A build which was 90%
complete would likely have a high "% match" for a fresh tmpdir so this
was added to try and give people a real idea of how much work remains
in a given build "up front" when you start the build.

The information is available in the [https://www.yoctoproject.org/docs/current/overview-manual/overview-manual.html#shared-state-cache official manual]

''Thanks to Richard Purdie for [https://www.openembedded.org/pipermail/openembedded-core/2018-August/272296.html clarifying that].''