When initializing a rootfs and requesting zypper to place its cache dir outside
of the rootfs:

> zypper --root /tmp/root --cache-dir=/root/zypper-cache install aaa_base

the rootfs ends up with some files that belong to zypper caches:

> # find /tmp/root/root/
> /tmp/root/root/zypper-cache
> /tmp/root/root/zypper-cache/solv
> /tmp/root/root/zypper-cache/solv/@System
> /tmp/root/root/zypper-cache/solv/@System/solv.idx
> /tmp/root/root/zypper-cache/solv/@System/solv
> /tmp/root/root/zypper-cache/solv/@System/cookie

I expect that all zypper cache objects are stored in /root/zypper-cache
instead.