Cargo 的配置文件查找顺序：

- /projects/foo/bar/baz/.cargo/config
- /projects/foo/bar/.cargo/config
- /projects/foo/.cargo/config
- /projects/.cargo/config
- /.cargo/config
- $CARGO_HOME/config which defaults to:
    - Windows: %USERPROFILE%\.cargo\config
    - Unix: $HOME/.cargo/config

详细配置查看官方文档：https://doc.rust-lang.org/cargo/reference/config.html