%{_host} different in FC and FE build environments

[Roozbeh Pournader]

I was playing with an SVG rendering problem I had on a box that stopped
gnome-games from working, and after a lot of debugging I found that it
was because I had compiled the gtk2 package myself, but was using FC4's
librsvg2. Now, librsvg2 runs this in it's %post:

%{_bindir}/update-gdk-pixbuf-loaders %{_host}

The %{_host} macro, expanded at build time, had resulted in
"i386-redhat-linux-gnu". But gtk2, which I had rebuilt using a stock
FC4's rpmbuild, had that %{_host} macro expanded to
"i686-redhat-linux-gnu" (as defined in /usr/lib/rpm/macros). This
resulted in an error message and all.

I tried --target i386, I tried setarch i386, I tried mock, and I still
got i686. The only way I could fix this was through defining redefining
_host explicitly in my '.rpmmacros'.

So, this means that the defaults used for building FC (beehive and co)
is different from the FE ones (mock and co). This needs to be fixed, or
to say the least, will result in weird things if we move, say, libwmf
from core to extras.

The question is: where should this be fixed? rpm? mock? beehive? where?

I would prefer rpm (because that will have minimum change, and will
enable people who just use plain rpmbuild), but wanted to ask before I
file a bug.

roozbeh