We need a build (maybe under the qa buildset) that basically does this: $ . oe-init-build-env build1 $ bitbake core-image-sato $ cd .. ; rm build1 $ . oe-init-build-env build2 $ bitbake core-image-sato Build2 should reuse all of the sstate from build1, but as build1 doesn't exist anymore any references to it in sstate will fail.
may also want to source oe-init-build-env from outside the poky dir. For example refkit has a current bug where the in dir sourcing works bit sourceing the init script from say /cow, does not.
nightly-qa-extras now includes extra steps to: * build core-image-sato * generate a locked-sigs.inc * delete the contents of tmp * generate a new auto.conf with a different TMPDIR value and the locked-sigs file included * builds core-image-sato http://git.yoctoproject.org/clean/cgit.cgi/yocto-autobuilder/commit/?id=5d80b30d55c134aeca63643b4ef3611a1845c6d1