kmod arch, ExlusiveArch, and buildsys?

[Warren Togami]

Hi Dan,

I am supposed to ask you about your opinion about how to ask buildsys to 
build for specific archs for a kernel module.  I believe that we should 
use ExclusiveArch with explicit listed archs, and buildsys should loop 
through each listed arch and build each.  This would also work for 
multi-arch performance intensive userspace packages similar to what we 
do in glibc or openssl in Core. [1]  Contributors may also list any 
other arch like s390x or alpha in ExclusiveArch, and buildsys simply 
ignores it if it isn't supported in Extras.

I believe this is the best approach to take for Extras, because Core has 
been similar to this for many years.  Do you have any opinion on this, 
or know of a better way to handle this?

Here is some related discussion:
<scop> the problem with exclusivearch is that let's say you list i586 
i686 x86_64 ppc and someone wants to rebuild it for alpha -> won't 
build, even if the package/software would work
<warren> scop, you can include other archs in the list, buildsys can 
simply ignore Extras non-supported archs.
<scop> warren, it's abuse of the tag nevertheless
<warren> scop, I'd personally disagree, but either way this is very 
simple and it already behaves similar to this in Core literally forever.
<warren> more importantly the simplicity of this allows us to move 
forward sooner
<warren> (assuming dcbw doesn't have a better idea)
<scop> that I agree with

Warren Togami
wtogami at redhat.com

[1]
However we should disallow this, unless someone proves through 
benchmarks that there is a huge benefit of publishing both i386 and i686 
packages and our tools support selection of the right arch directly. 
Currently I believe it doesn't.