[modified systems] FAQ entry proposal and more

["François Cami"]

Hello,

We've noticed time and again that some support requests in #fedora
stem from extensive modifications of users' systems. Kernels from
kernel.org, or xorg from git, come to mind. As a result, we seem to
have an informal policy stating that we do not support extensively
modified systems. Yet this policy is not present in the FAQ, and it is
sometimes non-trivial to make sure a user's system is not modified.

To facilitate checking for obvious modifications, I am considering:
* adding a --pretend option to yum, which coupled with
--distribution-synchronization and fpaste, which would enable us to
trivially know whether a system is both up to date and in sync with
what we're shipping at that precise moment.
* creating a script to gather other information, like the version of
both kernel and Xorg, the output of rpm -qVa, and the output of yum
--pretend --distribution-synchronization. This script could be
included in Fedora.
We already ship sosreport in sos.noarch but I think this is overkill
for our use.

As for the FAQ entry, this is my proposal:

== Keep to Fedora-provided packages ==
Please use the packages Fedora provides. Deviating from these can
render your system unstable or introduce bugs. You should exercise
caution before adding software from third-parties, especially
unpackaged software.


I would like us to show openness to modifications though. Two specific examples:
* some users happen to need a kernel, or xorg stuff, from
updates-testing for their hardware to work. Of course this will break
other packages (the kmods from rpmfusion come to mind), but I feel we
can manage such situations, or at the very least explain what could
break when doing that.
* some users request support after breaking their systems, for
instance while installing proprietary drivers with upstream
installers. I don't think we should stop at saying "not supported" in
this case, especially if said user asks how to repair his system
(which is something we can help with most of the time).

Please let me know what you think. Comments and flames both welcome :)

Cheers

François