Function cargo::ops::cargo_package::get_registry

fn get_registry(
    gctx: &GlobalContext,
    pkgs: &[&Package],
    reg_or_index: Option<RegistryOrIndex>,
) -> CargoResult<SourceId>

Determine which registry the packages are for.

The registry only affects the built packages if there are dependencies within the packages that we’re packaging: if we’re packaging foo-bin and foo-lib, and foo-bin depends on foo-lib, then the foo-lib entry in foo-bin’s lockfile will depend on the registry that we’re building packages for.