%SOUP_SERVER_LISTEN_IPV4_ONLY and %SOUP_SERVER_LISTEN_IPV6_ONLY
only make sense with soup_server_listen_all() and
soup_server_listen_local(), not plain soup_server_listen() (which
simply listens on whatever kind of socket you give it). And you
cannot specify both of them in a single call.
Options to pass to soup_server_listen(), etc.
%SOUP_SERVER_LISTEN_IPV4_ONLY and %SOUP_SERVER_LISTEN_IPV6_ONLY only make sense with soup_server_listen_all() and soup_server_listen_local(), not plain soup_server_listen() (which simply listens on whatever kind of socket you give it). And you cannot specify both of them in a single call.