Cargo Error: failed to get `x` as a dependency of package解决方法

在使用Cargo运行或编译有依赖的程序时，可能会出现类似下面这种错误：

PS D:\hocn\Desktop\rust\a1> cargo run    
    Updating crates.io index
error: failed to get `image` as a dependency of package `a1 v0.1.0 (D:\hocn\Desktop\rust\a1)`

Caused by:
  failed to load source for dependency `image`

Caused by:
  Unable to update registry `crates-io`

Caused by:
  failed to fetch `https://github.com/rust-lang/crates.io-index`

Caused by:
  failed to authenticate when downloading repository: git@github.com:rust-lang/crates.io-index

  * attempted ssh-agent authentication, but no usernames succeeded: `git`

  if the git CLI succeeds then `net.git-fetch-with-cli` may help here
  https://doc.rust-lang.org/cargo/reference/config.html#netgit-fetch-with-cli

Caused by:
  error authenticating: unable to connect to agent pipe; class=Ssh (23)

原因

默认情况下，Cargo是通过内置的git库来下载依赖的，有时会因为验证原因导致失败；

解决办法

• 找到.cargo目录，以Windows系统为例：C:\Users\hocn\.cargo，注意用户名；
• 进入.cargo目录，编辑文件config.toml，如没有则创建；
• 写入以下内容：

[net]
git-fetch-with-cli = true

git-fetch-with-cli默认为false，表示使用内置的git库来下载依赖；为true时，使用git程序来下载依赖，这样就不存在验证失败的问题；

请确保你安装了git程序并正确配置；