I'm working on a custom channel with a few rust packages. How do I expose the crates that are defined in rust-crates.scm since those are not using define-public? More specifically, my package builds in the guix source tree with ./pre-inst-env and the necessary modifications to rust-crates.scm and rust-apps.scm, but it does not build in my custom channel as it's unable to find the necessary crates. What mechanism is used internally by guix to expose the crates in rust-crates.scm to rust-apps.scm ?
