As per policy: > This usage of Replaces only takes effect when both packages are at > least partially on the system at once. It is not relevant if the > packages conflict unless the conflict has been overridden.
If I get this paragraph right, this will never happen since cppzmq breaks zeromq3 << 4.3.4-3 anyway and a) zeromq3 has no dependency on cppzmq at all b) cppzmq is in a different source package, so dpkg will upgrade zeromq3 and then install cppzmq At least I had no installation problems. Let me know if I got this wrong. Regards, Stephan