What's stopping Guix from building static binaries for various targets?

Guix can build for various different targets using `guix build --target `, and it can build entire linked libraries that can be deployed as a tarball to a target machine via `guix pack --target `...

But it can't do the one thing that Nix can do reliably and that is produce a single static binary.

What is stopping it?

Many packages are written using the `(build-system gnu-build-system)` macro.

How hard is it to add a `(build-system gnu-build-system 'static)` parameter, that changes the configure step to use the `-static` flag?