Bug#357939: Mixing release and debug mode
Ok, I think I've found the reason for the crashes: packagesearch is
written using dynamic plugins, the dynamic plugins can be compiled with
different setting than the main application.
If I mix debug and release versions (e.g. the plugins in release and the
main application in debug mode) the crash occurs. If I have a pure
release or debug system it seems to work fine.
Due to my screwed up build system, I didn't notice this before.
However, I think this should still be considered a bug.