Libzmq provides cmake packaging files only when it is compiled via cmake: /usr/share/cmake/ZeroMQ/ZeroMQConfig.cmake /usr/share/cmake/ZeroMQ/ZeroMQConfigVersion.cmake /usr/share/cmake/ZeroMQ/ZeroMQTargets.cmake These files are not generated when compiling libzmq via autotools, as is the case with the current ebuilds. The impact of the missing packaging files is that projects depending on zeromq which use cmake to build must provide their own logic for finding the library instead of using the upstream-provided files.