On Tue, 5 Oct 2010 19:46:53 -0500
BJ Dierkes <wdierkes(a)5dollarwhitebox.org> wrote:
NOTE: This is likely a topic to revisit/finalize in the next EPEL
SIG
Meeting (every Monday at 19:30 UTC).
Hello all,
I would like to start an official discussion regarding the current
policy on conflicting packages. Currently, the EPEL documentation
[1] is a bit sparse and does not reflect certain situations (such as
the discussion on mod_python26/mod_wsgi26). Per the FPG [1], Fedora
packagers should avoid an explicit 'Conflicts: xxxxx' as much as
possible. However, due to some new developments in EPEL 5 (namely
python26), some situations may require explicitly conflicting
packages.
As an example, during my package review for mod_python26 [3] the
subject was brought up due to my use of 'Conflicts: mod_python' in
the spec for mod_python26. The packages conflict because mod_python
and mod_python26 both provide the 'python_module', and the same
Apache directives when enabled. Therefore, the two can not be loaded
at the same time. The issue would be the same for mod_wsgi and
mod_wsgi26 (built against/for python26). In this specific situation,
the possible solutions to work around this are:
* Change policy to account for situations like those related to
python26 and allow explicit 'Conflicts: xxxxx'
* Silently disable mod_python26 if python_module is already loaded
via IfModule [4]
Though the second option (IfModule) is a cleaner approach, it hides
the fact that mod_python26 just won't load if mod_python is
installed/enabled and assumes the user will know to look
at /etc/httpd/conf.d/mod_python26.conf for comments on why that might
be. On the other hand, conflicting with mod_python doesn't inform
the user why it conflicts... it just conflicts. In my opinion it
would be slightly more obvious why mod_python26 would Conflict:
mod_python, but I don't know what is collectively in the best
interest of EPEL maintainers.
In Fedora, an explicit 'Conflicts: xxxxx' is unwanted behavior and
would be troubling/confusing for a lot of users. However, being that
EPEL is a different audience and different use case... I would like
to open discussion regarding current policy and determine,
officially, how these situations should be handled.
So, some more questions I have:
* Would this conflicts case be restricted to just these python26-mod*
packages? Or is this more general? I can see the case for packages
that use a parallel installable stack and can't load at the same
time, but I worry that we should make sure this isn't used more
broadly.
* Perhaps it would be worth making sure we document and require adding
a 'README-conflicts' to any package that has these conflicts with a
more verbose description of why and with what they conflict? Or some
other way to get info to users as to why they conflict?
I guess I would be ok with the conflict in this corner case, but would
want to make sure we discuss/approve any further expansion of it
anywhere.
kevin