Bug#695244: which_deb fails when trying to build source cds from an archive that doesn't have i386 or amd64 binaries

[peter green <peter.green@postgrad.manchester.ac.uk>]

Package: debian-cd

I've been working on trying to build cd images for raspbian using 
debian-cd. While doing this I found that when building source cds 
which_deb only looks for i386 and amd64 packages files. If it finds 
neither it fails horriblly. This prevents building source CDs for 
derivatives that focus on specific non-pc architectures like raspbian.

By fails horriblly I mean that rather than the failure of which_deb to 
find a usable packages file being reported to the user the failure 
results in crazy values in makefile variables (e.g. directory names in 
variables which should contain file names) which in turn cause the build 
process to fail in ways that have no obvious relation to the real issue.

To get things working for raspbian I just added armhf to the list of 
architectures but this isn't really a good soloution in general.