Download dependencies that cargo won't, such as those that require authentication.

How to use

1. Add your alternate registry to ~/.cargo/config
2. Add registry = "[registry-name]" to any dependencies that use the registry
3. Run cargo update
4. Run cargo sideload --registry=[registry-name] in your crate's root
   • Set CARGO_SIDELOAD_ACCESS_TOKEN in your shell or use the --access-token flag if your download endpoint requires authentication.
5. Your crates are now in the local cargo cache. cargo will use the local copies rather than attempt to download them.

Current restrictions

1. Authentication is currently hardcoded for GitLab

Remaining Work

1. Generalize authentication