Description of problem:

'netcat -U' option is not supported by the Debian version of netcat.  It
appears that they use a 'netcat' which is based on a completely different
codebase from the one in Fedora.

Version-Release number of selected component (if applicable):

libvirt from CVS
Debian netcat 1.10

This is the problematic code in src/remote_internal.c:

        // Generate the final command argv[] array.
        //   ssh -p $port [-l $username] $hostname $netcat -U $sockname [NULL]
        cmd_argv = malloc (nr_args * sizeof (char *));
        if (cmd_argv == NULL) {
            error (NULL, VIR_ERR_SYSTEM_ERROR, strerror (errno));
            goto failed;
        }

        j = 0;
        cmd_argv[j++] = strdup (command);
        cmd_argv[j++] = strdup ("-p");
        cmd_argv[j++] = strdup (port);
        if (username) {
            cmd_argv[j++] = strdup ("-l");
            cmd_argv[j++] = strdup (username);
        }
        if (no_tty) {
            cmd_argv[j++] = strdup ("-T");
            cmd_argv[j++] = strdup ("-o");
            cmd_argv[j++] = strdup ("BatchMode=yes");
            cmd_argv[j++] = strdup ("-e");
            cmd_argv[j++] = strdup ("none");
        }
        cmd_argv[j++] = strdup (server);
        cmd_argv[j++] = strdup (netcat ? netcat : "nc");
        cmd_argv[j++] = strdup ("-U");
        cmd_argv[j++] = strdup (sockname ? sockname : LIBVIRTD_PRIV_UNIX_SOCKET)
;
        cmd_argv[j++] = 0;