The current autogen for noto-cjk is failing. The issue appears to be caused by further repo reorganizations, and the latest release has an associated source tarball that is empty and just contains directories, and is 3K in size.

If you look here:

https://github.com/googlefonts/noto-cjk/releases/tag/Sans2.004

– you will find "source tarball" is empty. And the artifact we may want to grab instead is the "All Variable TTF/OTC".