compile port into noux-pkg and native library

I have successfully compiled liblzma as a native Genode library, and I've compiled xz-utils as a noux package, but given that the two are in the same source tree, how do I compile xz-utils for noux using the native liblzma library? I'm not seeing any configure options that would allow building xz-utils for a precompiled liblzma rather than building the two together. Is there a good way to do this?

I recognize that what I'm trying to do isn't really necessary, but it still would be nice to get this to work. Aside from reducing compile time, if I understand correctly, this should allow for multithreading, as that's all handled in the liblzma library, rather than in the command-line xz utility itself. Am I correct here?