[Dovecot] Using -module flag on sieve libs

[Dimitri]

> These are not plugins or modules. So this would likely be a bug. What 
> version is this? Could you show me the errors? Any idea which libraries 
> are missing?

Dovecot 2.1.12 + Pigeonhole 0.3.3, Mageia Linux (Cauldron), GCC 4.7.2.

Here is an excerpt from the build log (with Mageia's default flags,
including -no-undefined): http://pastebin.com/bYqiYRKJ

The library that is missing is
<dovecot-dir>/src/lib-storage/libdovecot-storage.la.

Dimitri