Which rpm version are you using ? For example rpm5 already have dropped
support
for builtin arch table  and  ancient  rpmrc  translation based on, possibily
faulty, uname(2).
From rpm-4.4.7 the --target option can also be used to set the arch.

Better info on this

https://lists.dulug.duke.edu/pipermail/rpm-devel/2006-April/000996.html

hth


On Tue, Apr 8, 2008 at 10:25 AM, Anders F Björklund <afb@rpm5.org> wrote:

> Pazzo Da Legare wrote:
>
>  I'm having problem with archs. I found the function rpmSetMachine
> > which change build_arch (of --showrc) I would like to change
> > programmatically (or better at compile time of my version of librpm)
> > other parameters: compatible build archs, install arch, install os,
> > compatible archs and compatible os's.
> > Could you please indicate which function/s should I use?
> > If possible, how to compile a library with archs' definitions?
> > What about compatibility with rpm version 4.4.x?
> >
>
> I believe you should be changing /etc/rpm/platform for those now.
> >
>
> --anders
>
>
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