如何通过VSCode或rust-analyzer配置解决Rust crate认证缺失问题

问题场景 #

使用VSCode的rust-analyzer插件时，出现Cargo元数据加载失败的错误，核心原因是拉取Git依赖时SSH认证失败，具体错误日志如下：

[ERROR rust_analyzer::lsp_utils] rust-analyzer failed to load workspace: Failed to read Cargo metadata from Cargo.toml file /Users/calvin/tiflash/raft-engine/Cargo.toml, Some(Version { major: 1, minor: 64, patch: 0, pre: Prerelease("nightly") }): Failed to run `"cargo" "metadata" "--format-version" "1" "--manifest-path" "/Users/calvin/tiflash/raft-engine/Cargo.toml" "--filter-platform" "x86_64-apple-darwin"`: `cargo metadata` exited with an error:     Updating git repository `https://github.com/pingcap/rust-protobuf`
    Updating git repository `https://github.com/tikv/raft-rs`
error: failed to load source for dependency `raft-proto`

Caused by:
  Unable to update https://github.com/tikv/raft-rs?branch=master

Caused by:
  failed to fetch into: /Users/calvin/.cargo/git/db/raft-rs-42b8049ef2e3af07

Caused by:
  failed to authenticate when downloading repository: git@github.com:tikv/raft-rs

  * 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:
  no authentication available

临时解决办法 #

在终端执行以下命令启动SSH代理并添加密钥后，从命令行启动VSCode可临时解决问题：

eval `ssh-agent -s`
ssh-add
# 执行 code . 启动VSCode

更简洁的配置解决方案 #

无需每次从命令行启动VSCode，可通过以下两种方式永久解决：

1. 修改Cargo配置，使用Git CLI拉取依赖 #

在全局Cargo配置文件~/.cargo/config.toml，或项目级配置文件项目根目录下的.cargo/config.toml中添加以下内容：

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

该配置会让Cargo调用系统Git CLI拉取依赖，而非内置Git实现，自动继承当前环境的SSH认证信息。

2. 配置VSCode让rust-analyzer继承SSH Agent环境变量 #

如果上述方法无效，可在VSCode的settings.json中添加环境变量配置，确保rust-analyzer运行时能获取到SSH认证所需的环境变量：

{
  "rust-analyzer.cargo.extraEnv": {
    "SSH_AUTH_SOCK": "${env:SSH_AUTH_SOCK}"
  }
}

注意：需确保系统已自动启动SSH代理（可在~/.zshrc或~/.bashrc中配置自动启动ssh-agent的脚本），否则VSCode无法读取到有效的SSH_AUTH_SOCK变量。

内容的提问来源于stack exchange，提问作者calvin