Created attachment 1874 [details]
Sstate archives only in build/sstate-cache, not build2/sstate-cache

It seems that doing a build using an sstate mirror results in an SSTATE_DIR which is missing archives that are necessary to do a build entirely from sstate. How it manages to successfully complete a build without things it seems to think are required, is a question I'd like to find the answer to.

Reproduction steps:
- source poky/oe-init-build-env build
- bitbake core-image-minimal # populate from scratch
- exit

- source poky/oe-init-build-env build2
- echo "SSTATE_MIRRORS = 'file://.* file://${TOPDIR}/../build/sstate-cache \n '" >conf/auto.conf
- bitbake core-image-base
- find tmp*/stamps/ -type f | grep -Ev '(setscene|do_build|do_package_write|do_rootfs)' # note that there's no output here, it built entirely from sstate using the mirror

- sed -i -e '/SSTATE_MIRRORS/s/^/#/' conf/auto.conf
- bitbake -S printdiff core-image-base # note the many differences found, particularly in do_fetch, but no details
- exit

- source poky/oe-init-build-env build3 # to keep the broken build2 sstate-cache isolated
- echo "SSTATE_MIRRORS = 'file://.* file://${TOPDIR}/../build2/sstate-cache \n '" >conf/auto.conf
- bitbake core-image-minimal # Watch it use a ton of setscenes, but still rebuild nearly everything from scratch

If you compare build/sstate-cache to build2/sstate-cache at a file level, you'll see the files listed in the attachment exist only in the from scratch build, but not in build2.