Fedora 17 in a CHROOT on Ubuntu - and the wrong dependency on rpmlib(X-CheckUnifiedSystemdir)

[Suvayu Ali]

Hi Bill,

On Fri, Sep 14, 2012 at 10:31:20AM -0400, Bill Davidsen wrote:
> Marc Wäckerlin wrote:
> >Hi
> >
> >I am working in Ubuntu and compiling RPMs for Fedora. That's why I install Fedora in
> >a **chroot** environment. That works fine with Fedora 16, but fails with Fedora 17 due
> >to the wrong "rpmlib(X-CheckUnifiedSystemdir)" dependency.
> >
> >I Do not upgrade and I cannot use dracut, because Fedora 17 is in a chroot and cannot
> >boot. So the instructions at http://fedoraproject.org/wiki/Upgrading_Fedora_using_yum
> >do **not** help.
> >
> >How to solve the problem? What does dracut do, why(*) does rpm fail, where does this
> >dependency come from? How can I either fake this dependency or prevent RPM from requiring
> >it? I need a deep inside knowledge on what's going on, what dracut does and what rpm does.
> >What have the fedora-guys patched to get thie wrong dependency, and how can I undo it?
> >
> >----
> >(*) I mean technically *why*, not user-view answers like "to prevent upgrades without
> >fs-migration", this kind of answer does not help, but technical answers like "dracut
> >creates content X in file Y, then the dependency is ignored in rpm"
> >
> Marc, I have to ask why you are doing that as opposed to just creating a VM
> and running Fedora in that. It just seems so much easier. And I have friends
> running fc17 in VM on both Mac and Windows7, so it's pretty sure Ubuntu
> would do so as well.
> 
> Just curious why you took that approach.
> 

I have a similar build system for SLC 5.7.  Our software can also be
deployed in a VM; I have tried that but found the overhead of using a VM
(build times, test job run times and the fact that you have to have a
working virtualisation setup) rather large.  Instead now I (and many of
my colleagues) use a few scripts to maintain the chroot system for our
software.  This also seems easier to implement across multiple linux
distros without much fiddling (it's after all a few scripts that uses
chroot to setup the environment).  To give you an idea about the "easy
on various" distros bit, we have tried this on Arch, Ubuntu, Fedora and
Debian.  Getting it to work on Fedora required some extra effort to get
the SELinux labels for the chroot'ed directory hierarchy correct.

Hope that answers your question.

-- 
Suvayu

Open source is the future. It sets us free.