[xen-tools] xen-tools error checking, reloaded

[Henning Sprang]

Hi,
I write this not into the debian bts because I am playing around with
xen-tools on fedora, so it's trictly not a Debian Bug. I have to
prepare a FAI presentation and want to show that all these things also
work when somebody's most loved distribution is something else than
debian, but one wants to have the great feature of xen management and
automatic installation :)
All the debian stuff (which is the FAI installserver, currently, until
we tested it somewhere else - should not be too much) will reside in
VM created with xen-tools.

So, all looks quite fine, after installing an "alienated" debootstrap
0.3.X rpm and running xen-tools, it finishes with

--- start ---
Creating Xen configuration file
Done
All done

Logfile produced at:
         /var/log/xen-tools/xen-tools-fedora-test.log
--- end ---

Doesn't exactly look like an error. But then, I can't start the vm,
and see in the logs that I forgot to install the perl template
modules.

This is already much better than previous versions, the error can be
found easily in the log file, and there's no half-finished lvm volume
with no matching config file as some versions before - very cool.

Still, to be more user friendly, users should not have to wait until
the end (debootstrap, some minutes, more when no local mirror is
available, e.g. because one makes his first tests of xen-tools on
fedora), then see something which is not directly an error message,
and then look in the logfile for such a simple thing, that could be
tested in make install, or at least/latest at the very start of
xen-create-image, leading to fast failure.

Henning