anchor.diff:        consoles = mkOption {
           type = types.listOf types.str;
           default = let
  -          consoles = [ "${qemuSerialDevice},115200n8" "tty0" ];
  +          consoles = [ "${qemu-flags.qemuSerialDevice},115200n8" "tty0" ];
           in if cfg.graphics then consoles else reverseList consoles;
           example = [ "console=tty1" ];
           description = ''
  
positive.code: 
        networkingOptions =
          mkOption {
            default = [
              "-net nic,netdev=user.0,model=virtio"
              "-netdev user,id=user.0\${QEMU_NET_OPTS:+,$QEMU_NET_OPTS}"
            ];
            type = types.listOf types.str;
            description = ''
              Networking-related command-line options that should be passed to qemu.
              The default is to use userspace networking (SLiRP).
  
              If you override this option, be advised to keep
              ''${QEMU_NET_OPTS:+,$QEMU_NET_OPTS} (as seen in the default)
              to keep the default runtime behaviour.
            '';
          };
  
negative.code:           '';
        };
  
      virtualisation.forwardPorts = mkOption {
        type = types.listOf
          (types.submodule {
            options.from = mkOption {
              type = types.enum [ "host" "guest" ];
              default = "host";
              description =
                ''
                  Controls the direction in which the ports are mapped:
  
                  - <literal>"host"</literal> means traffic from the host ports
                  is forwarded to the given guest port.
  
                  - <literal>"guest"</literal> means traffic from the guest ports
                  is forwarded to the given host port.
                '';
            };
            options.proto = mkOption {
              type = types.enum [ "tcp" "udp" ];
              default = "tcp";
              description = "The protocol to forward.";
            };
            options.host.address = mkOption {
              type = types.str;
              default = "";
              description = "The IPv4 address of the host.";
            };
            options.host.port = mkOption {
              type = types.port;
              description = "The host port to be mapped.";
            };
            options.guest.address = mkOption {
              type = types.str;
              default = "";
              description = "The IPv4 address on the guest VLAN.";
            };
            options.guest.port = mkOption {
              type = types.port;
              description = "The guest port to be mapped.";
            };
          });
        default = [];
        example = lib.literalExample
          ''
          [ # forward local port 2222 -> 22, to ssh into the VM
            { from = "host"; host.port = 2222; guest.port = 22; }
  
            # forward local port 80 -> 10.0.2.10:80 in the VLAN
            { from = "guest";
              guest.address = "10.0.2.10"; guest.port = 80;
              host.address = "127.0.0.1"; host.port = 80;
            }
          ]
          '';
        description =
          ''
            When using the SLiRP user networking (default), this option allows to
            forward ports to/from the host/guest.
  
            <warning><para>
              If the NixOS firewall on the virtual machine is enabled, you also
              have to open the guest ports to enable the traffic between host and
              guest.
            </para></warning>
  
            <note><para>Currently QEMU supports only IPv4 forwarding.</para></note>
          '';
      };
  
      virtualisation.vlans =
        mkOption {
          type = types.listOf types.ints.unsigned;
  