Dirmngr is supposed to be used as a system wide daemon, it should be started like:
dirmngr --daemon
This will force it to go into the backround, read the default certificates (including the trusted root certificates) and listen on a socket for client requests. It does also print information about the socket used but they are only for compatibilty reasons with old GnuPG versions and may be ignored.
For debugging purposes it is also possible to start Dirmngr in the foreground:
dirmngr --server -v