Comment # 3 on bug 1081435 from Manfred Hollstein

Yes, rpmqpack is in $PATH and is available at /usr/bin

As I wrote, the issue was caused by some empty /var/lib/rpm which appears to
just have been initialized (as in "rpm --initdb"), but not filled with content.
When I replaced /var/lib/rpm with a symbolic link to /usr/lib/sysimage/rpm,
everything worked as expected. I basically forgot to close this issue.