It would be awesome if buildhistory could detect if it were running in a git repo and write the layer SHAs to the repo somewhere, like bitbake does when it starts up. When my buildhistory log is "bitbake core-image-sato" 20 times it would help to differentiate what build was what.
Unless I'm misunderstanding the request, it already does this in two places - metadata-revs at the root of the buildhistory repo (machine-readable, written out on every build), and build-id.txt under the directory for an image (only written when building an image, and the format is the same as bitbake's preamble output).
You're not mistaken. Would it be convenient/possible/useful to put this into the commit log to?
Implemented in master: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=734411a9e633f5b1459216e4cc5175f267d8a668
Verified on master: cat buildhistory/metadata-revs meta = master:71b0568fa43285f0946fae93fb43cea5f3bbecec meta-yocto = master:71b0568fa43285f0946fae93fb43cea5f3bbecec meta-yocto-bsp = master:71b0568fa43285f0946fae93fb43cea5f3bbece