'policy' for multiple versions of same software in EPEL

[Greg Swift]

On Fri, Oct 12, 2012 at 4:53 PM, Kevin Fenzi <kevin at scrye.com> wrote:
> On Wed, 10 Oct 2012 13:13:41 -0500
> Greg Swift <gregswift at gmail.com> wrote:
>
>> So... I've paid attention to the conversations around this because i
>> was a long time zabbix user, so it affected me in that I had to build
>> my own 'latest' packages usually or download from the maintainer's
>> personal repository.  If I remember correctly it has also been
>> discussed around lots of web apps like bugzilla as well.
>
> Yeah.
>
> There's a lot of apps out there that have a different release cycle
> that RHEL has, so we have to try and adjust to that. Keeping in mind
> that most people who are using RHEL don't like things changing very
> much.

I'm all for that.  Technically its one of the benefits of them being
different package namespaces that conflict, you won't get a change you
don't force with intent :)

> ...snip...
>
>> So the two scenarios I'm looking at:
>>
>> 1: collectd [3] - to make version 5 available in epel5/6 will have to
>> submit collectd5 package.  Most of the work is done, but right now the
>> created package 'conflicts' due to duplicate library files and the
>> perl-Collectd module needing to be renamed.  I can usually package up
>> software pretty readily, and I don't know how to do what is needed to
>> do this without more guidance (more admin than dev).  Because of what
>> the software is, I'd imagine most people are running either version 4
>> or version 5.  Some people might be running both environments from the
>> server side (separate collectors), but aren't likely to have a
>> monitored (client) system active in both.
>
> Right. I think this may be something we want to ask the Fedora
> Packaging folks (who live on the packaging list) about.

good plan

> The main problem with conflicts is that it's something that is detected
> by yum at the 'test' stage. It means you have chosen, downloaded a
> bunch of stuff and then yum tells you, "WOAH, these confict, fix it and
> try again". This is not very friendly. If you do this in the installer
> it's even worse.

that is unfortunate

> In this case I guess your reasoning makes sense to me, people are
> unlikely to want to run both at the same time on clients. However, on
> servers they might... what parts of them would conflict?

hmm... still tough to justify running simultaneous on the same server.
 Maybe I've just always had machines available (both virtual and
physical) .  That being said, i wonder if we make the packages support
--prefix if the customer can override and make it work?

I just don't think we should spend a lot of time and resources trying
to make something work for the sub1% that are doing something uncommon
and special in the first place.

However, If one of the people that wants that wants to chip in and
provide use case, testing, and preferably patches that would be
awesome.

>> 2: rubygem-rspec (no associated bugzilla entry that I am aware of yet)
>> - to make rspec-puppet available in epel 5/6 version 2 of rspec needs
>> to be made available.  I assume this means that the same general
>> concept of rspec2 package needing to be initiated begins.  With this
>> one there appears to be way more impact as there are at least 3
>> packages that build on top of rspec currently. [4] Because this is
>> more of a library set of packages, and most of those packages perform
>> different functionality for rspec that may not always be for the same
>> end use cases it makes conflicts a harder possibility.  So i'd imagine
>> either a) have to do a parallel installable rspec2 release of all of
>> them that conflicts so that the 'gems' themselves don't need to be
>> adjusted or b) adjust the entire rubygem so that it behaves as rspec2
>> and make the other gems use rspec2 rather than rspec.
>
> Well, this is a reasoning for rspec2 to be completely parallel
> installable. Can't those things that wish continue to use rspec1?
> Or would that lead to mixing them both since they are in the same
> stack?

They are decidedly incompatible versions, but definitely the same
stack and namespace.  since they run on the same version of ruby, its
not like we get a separation that way.

For any EPEL users that use rubygem-rspec (which has nothing built
against it.. see footnote in previous message), the rubygem-rspec2
would be a conflict and non-obsolete so they could keep on keeping on,
even update if there was one (which I don't believe there is or ever
will be based on rspec state).

With this example, i don't see why you'd want both versions.  However,
I know that is not always going to hold true.

I guess maybe a series of scenarios being documented with suggestions
on handling would be best?