The resolver = "2" parameter is missing from the [workspace] section. Since Rust 1.51.0, Cargo has opt-in support for a new feature resolver that will be the default resolver for the new Rust editions starting with edition 2021. It needs to be enabled in the entire workspace. You can do that by either adding resolver = "2" parameter or edition = "2021" in the workspace parameter which will automatically infer resolver = "2". Could you please update your pull request to include one of these changes?
Understood :+1: