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= Upstream Versioning Recommendation (Draft) =
= Upstream Versioning Recommendation (Draft) =


This text tries to communicate with upstream projects about implications of  
This text tries to communicate with upstream projects about implications of different kind of software versioning schemes from downstream point of view.  
different kind of software versioning schemes from downstream point of view.  


While listing the schemes that cause more workload and attention in downstream,
While listing the schemes that cause more workload and attention in downstream,it also gives a recommendation that should work for most of the upstreams and straight forward for packager. For each upstream project it is their own decision to choose best practice.
it also gives a recommendation that should work for most of the upstreams and is
harmless and straight forward for packager.





Revision as of 20:07, 12 January 2011

DocsProject Header docTeam1.png


Upstream Versioning Recommendation (Draft)

This text tries to communicate with upstream projects about implications of different kind of software versioning schemes from downstream point of view.

While listing the schemes that cause more workload and attention in downstream,it also gives a recommendation that should work for most of the upstreams and straight forward for packager. For each upstream project it is their own decision to choose best practice.


Note.png
Document role
Note that this is only a recommendation and its role is only informal.

Motivation

Software release versions are important. They are used by many software like dpkg and rpm, but also their network counterparts like apt and yum which all use versions to determine is given version newer or older compared to another. Versions are cornerstones of automation but also play vital role for software compatibility when dependency chains grow large.

Some versioning schemes need more attention than others when packaged into distribution specific packages. If a package maintainer fails pay that attention, future upstream releases may have versions that break automatic package upgrade path meaning that with given versions, package will not get updated automatically.

When successfull, all this extra workload and attention is lost work hours and away from more productive distribution work, causes extra package builds in build system (equals to loss of computing power, storage and electricity) even may cause problems for end users. Thus all of it should be avoided if possible.

Anatomy of RPM Version

describe it here, complete nevr and make it simple


Ugly Workarounds

If a packager fails to convert an upstream version into correct package version+release combination and such build ends up into official Yum repositories, that forces packager to add an Epoch tag into package metadata:

Warning.png
Quote from Packaging Guidelines: Use of Epochs
The Epoch tag in RPM is to be used only as a last resort, and should be avoided whenever possible. However, it is sometimes necessary to use an Epoch to handle upstream versioning changes or to ease transition from third party repositories.

Use of Epoch is irrevocable decision for package whole lifespan and causes even more attention in future package updates.

Problematic Cases

While Packaging Guidelines describes these cases in great detail, here we outline an abstract of the issue. The main source of the problems is non-numeric symbols in version. There are three cases when these are typically used:

  • pre-release versions
  • snapshot versions
  • post-release versions

In these cases, Packaging Guidelines describe how these string parts in version may have to be moved into package Release Tag.

Optimal Versioning

Projects should avoid using non-numerical versions.

list examples with different major + minor combinations

list examples of projects which tackle different releases (pre-, snap-, post) without non-numeric parts

See Also