I'm *sure* we'd already done this but systemd really likes tmpfs to have support for ACLs. Can we enable CONFIG_TMPFS_POSIX_ACL in the default kernel configuration?
I thought this was on as well, perhaps with the new factored out standard kernel and developer kernel types it was disabled. I'll have a look.
Strangely, this only seems to be on for the minnow board, which is not where it belongs. We'll have to create a fragment and move it to a more global spot.
Patches to add this have been submitted to the linux-yocto mailing list and are pending review/integration.
Fixed. See commit 1f501a8f6e7b7f2d79bf2a18a8b83f413eb5cc19 in openembedded-core.