~kanarip

Just for fun, I started building ruby-1.8.6 and ruby-1.9.1 packages for Enterprise Linux 5. These would be opt-in repositories, "channels" if you will, fast-tracking an Enterprise Linux 5 box to newer versions of Ruby, and many of the packages that depend on Ruby one way or the other (such as Ruby on Rails packages, and many Ruby Gems).

I started out with the Fedora packages, obviously, and after getting a bunch of packages in said repositories, and testing and patching and rebuilding a bunch of times, it became obvious;

For the type of situation where you want two of these "fast-track" repositories, or even just multiple versions of the same packages built under different conditions, it turns out to be mandatory that a Koji build of a certain package contains a globally unique package NEVRA (Name, Epoch, Version, Release, Architecture), so they can be distinguished between the two (very much different) versions of the package. That is to say, one package NEVRA can only be built once, and can only be duplicated to other destination tags.

Example: The ruby-shadow package (a requirement for Puppet, which makes it very important to me) is binary compiled, either against ruby-1.8.6 or ruby-1.9.1. For one version (e.g. upstream's 0.9.7) to be available through both repositories, one builds ruby-shadow-0.9.7-1.el5.src.rpm.

I build the package against two Koji build targets, each one using a build tag that causes a buildroot to be created with either ruby-1.8.6 or ruby-1.9.1; in my case these build targets are feature-el5-ruby-1.8.6 and feature-el5-ruby-1.9.1.

Koji however will only allow one specific package NEVRA to be built just once. But, ruby-shadow-0.9.7-1.el5.src.rpm has to be built twice; once for ruby-1.8.6, and once for ruby-1.9.1. Since one build with the same NEVRA already exists, another cannot be built.

Ergo, you need some kind of indication of the build-root/build-tag/destionation-tag in the package NEVRA...

And we go off rebuilding everything again... ;-)