* Andreas Beckmann <anbe@debian.org>, 2013-04-25, 21:27:
what would be the correct severity?
I've been using important (or normal, if only toy^Wexotic architectures were affected) for such file conflicts, regardless of whether you were able to reproduce the bug in practice by co-installing the packages in question.
You might find this script useful: http://anonscm.debian.org/viewvc/collab-qa/multi-arch/report-multiarch-bug?view=markup -- Jakub Wilk