This bug is to track the need to refactor package_rpm.bbclass or fix rpm's inability to install packages in a predictable order. The problem is our image generation process is entirely package-based, and we need to ensure that, for example, base-passwd and shadow are installed before any packages that need to create custom users/groups. Likewise, postinst scripts should be able to assume that the RDEPENDS for this package have already been installed before they run (currently this is not the case - qemugl's postinst script had to be converted to a first-boot script for this reason).
I think this has been done via a number of patches to help control scriptlet dependencies, smart integration and related.