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 official manual

Thanks to Richard Purdie for clarifying that.