Bug#755705: cyrus-imapd-2.4: not binNMU safe

[Emilio Pozuelo Monfort]

Source: cyrus-imapd-2.4
Version: 2.4.17+caldav~beta9-9
Severity: serious

I was looking at why 2.4.17+caldav~beta9-9+b1 on s390x didn't migrate
a few days ago. Turns out there is a binNMU-safe issue. Take for example
cyrus-caldav-2.4. That package has:

Depends: cyrus-common-2.4 (= ${binary:Version}), ${shlibs:Depends}, ${misc:Depends}

Which in the binnmu got expanded to:

Depends: cyrus-common-2.4 (= 2.4.17+caldav~beta9-9+b1), libc6 (>= 2.15), libcomerr2 (>= 1.01), libdb5.3, libical1 (>= 1.0), libsasl2-2, libsqlite3-0 (>= 3.6.0), libssl1.0.0 (>= 1.0.0), libwrap0 (>= 7.6-4~), libxml2 (>= 2.8.0), zlib1g (>= 1:1.2.0), cyrus-common (= 2.4.17+caldav~beta9-9+b1)

Notice the final "cyrus-common (= 2.4.17+caldav~beta9-9+b1)"

Since cyrus-common is arch:all, version 2.4.17+caldav~beta9-9+b1 doesn't
exist, so cyrus-caldav-2.4 becomes uninstallable.

This happened to other packages from the same source, but I guess the
root is the same as it got expanded from misc:Depends.

For the full log, see:
https://buildd.debian.org/status/fetch.php?pkg=cyrus-imapd-2.4&arch=s390x&ver=2.4.17%2Bcaldav~beta9-9%2Bb1&stamp=1404727136

Emilio