Cargo install failed due to interfering with git proxy in Ubuntu Linux

[calidion]

Problem

when a global git https/http proxy config is set.

cargo install will fail with the following errors:

    Updating crates.io index
warning: spurious network error (3 tries remaining): [35] SSL connect error (OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to index.crates.io:443 )
warning: spurious network error (2 tries remaining): [35] SSL connect error (OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to index.crates.io:443 )
warning: spurious network error (1 tries remaining): [35] SSL connect error (OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to index.crates.io:443 )
error: download of config.json failed

Caused by:
  failed to download from `https://index.crates.io/config.json`

Caused by:
  [35] SSL connect error (OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to index.crates.io:443 )

after removing git config, cargo install will be normal again.

Steps

1. create a git config file in ~/.gitconfig
2. add the following config

[https]
	proxy = socks5://127.0.0.1:1080
[http]
	proxy = socks5://127.0.0.1:1080

3. execute cargo install

Possible Solution(s)

remove git proxy config for http/https.

Notes

No response

Version

cargo 1.85.0-nightly (769f622e1 2024-12-14)

[weihanglo]

Thank you for the issue report.

The config doc of http.proxy doesn't mention it respects git proxy settings. As far as I can tell, this is an undocumented behavior, which was implemented in 618137b in #541, way earlier than Rust 1.0 release.

I am not seeing any reason of this design in #541. Maybe it was because crates.io registry index was mainly downloaded via Git from rust-lang/crates.io-index, or it was just a handy default to help people use Git dependencies out-of-the-box.

Cargo has sparse registry support since 1.68. If people are not using any git dependencies, it is surprising that git proxy settings affect HTTP requests for normal cargo operations.

Having some possible approaches here:

• Completely remove the support of respecting HTTP proxy settings from git config. While this is an undocumented behavior, it might break someone's existing settings.
• Only respect git config if an http handle is going to talk to git (like git dependencies or crates.io-index from git repo).
• Keep the behavior as is and document it. It might still cause confusion like Should cargo config get print warning if proxy config found in git/libcurl ? #12572.

[weihanglo]

To me, since we want to rely less on a specific external, I am a bit inclined to remove the support, though the middle ground solution is not bad at all, and is consistent when net.git-fetch-with-cli enabled.

[calidion]

should keep it only for git, not for crates.io.

[calidion]

it seems not all cargo install will cause this problem.

[weihanglo]

See also #8327.