/usr/include/gnuradio/zeromq/ is in gnuradio-dev 3.7.9.1-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gnuradio/zeromq/api.h
/usr/include/gnuradio/zeromq/pub_msg_sink.h
/usr/include/gnuradio/zeromq/pub_sink.h
/usr/include/gnuradio/zeromq/pull_msg_source.h
/usr/include/gnuradio/zeromq/pull_source.h
/usr/include/gnuradio/zeromq/push_msg_sink.h
/usr/include/gnuradio/zeromq/push_sink.h
/usr/include/gnuradio/zeromq/rep_msg_sink.h
/usr/include/gnuradio/zeromq/rep_sink.h
/usr/include/gnuradio/zeromq/req_msg_source.h
/usr/include/gnuradio/zeromq/req_source.h
/usr/include/gnuradio/zeromq/sub_msg_source.h
/usr/include/gnuradio/zeromq/sub_source.h