$ GOOS=freebsd GOARCH=amd64 go build ./...
# github.com/godbus/dbus/v5
./transport_unix.go:52:3: cannot use t (type *unixTransport) as type transport in return argument:
	*unixTransport does not implement transport (missing SendNullByte method)
./transport_unix.go:58:3: cannot use t (type *unixTransport) as type transport in return argument:
	*unixTransport does not implement transport (missing SendNullByte method)