Comment # 16 on bug 1029961 from Ludwig Nussel

(In reply to Stanislav Brabec from comment #14)
> [...]
> As Michael wrote, there are only two chances to upgrade such system:
> 
> 1) lua pretrans magic
> 
> 2) direct rpm database manipulation

3) - do not package compat symlinks. Run something post install of
     each package that installs such links if /bin is a directory and
     the package /bin/$something in it's provides tags.
   - Make the initrd move away /bin and install the /bin -> /usr/bin
     symlink (same for sbin and lib).