core-image-minimal in master when built with sysvinit now contains shadow; in dylan that was not the case. This means /bin/login is now always provided by shadow, and thus the work that was done to provide that from busybox instead of tinylogin is not being utilised. I have traced this to the addition of "inherit useradd" to sysvinit in the following commit: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=f638364eff3b7a2de7953d154fb2451c51729911 I'm not sure what the correct solution to this is but this is clearly not desirable; if nothing else, core-image-minimal is about 1.2M larger than it needs to be with shadow installed.
A recent change to sysvinit inherited useradd, which caused the core-image-minimal image to gain about 1.2M with the shadow based tools. Since we now have a split busybox (with setuid), it has all the functionalify of shadow, so depend on that by default, if shadow is included in an image then the update-alternatives will kick in and override the busybox utilities.
Dug into this a little deeper today and it's getting interesting! So simply changing the RDEPENDS to busybox causes other breakage, I think because the rootfs is missing some required file that the name groupadd needs to operate correctly, but I also realized that systemd provides halt and shutdown also. So began wonder if we should not have the shutdown group simply be part of the core base-files for oe-core that would remove the useradd from sysvinit, but we will still have useradd in systemd for log and systemd-journal groups.
To Add shutdown group http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=5f9ee672a0c187fab6f0a60237796808457e6569 and Remove the useradd from sysvinit http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=e0a351b9131918d0ee7ade4c02f4e012a69dc837
Verified on master branch. Commit ID: 2b5bac02196b8bd30d223d508f5f7d4300889fd7