vendor_remote_repository generated alias targets don't work

[ashi009]

When set render_config(default_alias_rule = "opt") for vendor_remote_repository. The generated alias rules are not working with the following error:

ERROR: .../BUILD.bazel:254:12: error loading package '@@crate_index//': cannot load '@@crate_index//:alias_rules.bzl': no such file and referenced by '//...'

A closer look showed that the generated alias_rules.bzl is not included in the generated crate_index repo.

If I understood correctly, alias_rules.bzl contains no dynamically generated content, and could be directly referenced from rules_rust.