%{?dist}, recommended or optional?

[Michael Schwendt]

On Sat, 07 Jan 2006 12:51:40 +0330, Roozbeh Pournader wrote:

> I am encountering two (or even three) different approaches about the
> %{?dist} tag in Extras, which has made me somehow confused.
> 
> These are the somehow contradicting advices:
>
> http://fedoraproject.org/wiki/Extras/BuildRequests :
> 
>    It is recommended to use the suffix %{?dist} in the release field
>    to distinguish builds for different OS versions.
> 
> http://fedoraproject.org/wiki/PackageNamingGuidelines
> 
>    If you wish to use a single spec file to build for multiple
>    distributions, you can use the %{dist} tag in the Release field.
> 
> http://fedoraproject.org/wiki/DistTag
> 
>    It is documented and standardized so that maintainers who wish to use
>    it can do so.
> 
> So, the question is: how is a maintainer supposed to make his mind?
> Should he take the BuildRequests advice and use it, unless he has a good
> reason he shouldn't? Or should he take the other advices and do it only
> if he wishes to, or when he believes it's really *needed*?

Where is the part you find "somehow contradicting"? In all three quotes,
using %{?dist} is either recommended or described as being optional.
This dist tag macro exists in order to aid you. "recommended" is not
equal to "mandatory".

When not using %{?dist}, you need to find another way to ensure that
%{epoch}:%{version}-%{release} of a package for an older distribution is
"higher than" epoch:version-release of the package for a later distribution.
Without the dist tag, you would probably increment %release or make a big
jump to a much higher number, e.g.  FC3 => release 1, FC4 => release 10,
so all package releases for the later distribution are seen as newer.

(Btw, for distribution upgrades, which don't perform an online upgrade of
Fedora Extras packages prior to first boot, using %{dist} is insufficent.
[Same applies to CD based distribution upgrades. Any Fedora Extras update
package for the older distribution version may be seen as newer than a CD
snapshot copy of a Fedora Extras package for the newer distribution, e.g.
4.fc3 > 1.fc4, so while %{dist} is helpful for our current Fedora Extras
online repository, it is not a silver bullet.])