Comment 5 for bug 1075260

The code isn't throwing errors as it doesn't know if dpkg supports this option and therefore it is a perfectly fine case to get a non-zero exit here. At the time the code was written there was simple no way of detecting it, now there is dpkg --assert-multi-arch but that isn't supported by all dpkg's which support --print-foreign-architectures, so we just don't bother to try for now as it introduces more problems than it solves.