Description of Problem:
rpmbuild doesn't seem to parse commas in ExcludeArch directives right.
Steps to Reproduce:
1. put "ExcludeArch: arch1, arch2" in a spec file.
2. rpmbuild on arch1
I think it build on arch1 (though not on arch2 as expected).
It shouldn't build on arch1 nor arch2.
According to http://www.rpm.org/max-rpm/s1-rpm-specref-preamble.html,
ExcludeArch requires the architectures to be delimited by spaces, not commas.
ExcludeArch: sparc alpha