The LCG libzeromq is linked to libsodium, but pkg-config doesn't seem to propagate this, so explicitly search for and link to it. libsodium seems to be installed as a system library in all test systems, so this was not observed before.
The LCG libzeromq is linked to libsodium, but pkg-config doesn't seem to propagate this, so explicitly search for and link to it. libsodium seems to be installed as a system library in all test systems, so this was not observed before.