'cargo publish' ignores non-default ports during artifact upload on non-windows OS

[bhamail]

Problem

While working on a Nexus repository plugin for cargo, we discovered a problem that is only visible when running on non-Windows OS: The command:

cargo publish --index http://localhost:8081/repository/c2/index --token ...

will succeed in updating the index, but will fail when attempting to upload the compiled artifact. The error looks like this:

...
    Finished dev [unoptimized + debuginfo] target(s) in 0.60s
   Uploading loops v0.1.0 (/Users/bhamail/sonatype/community/rust/projects/loops)
[2019-02-26T15:40:36Z DEBUG cargo] exit_with_error; err=CliError { error: Some(Error { description: "Couldn\'t connect to server", code: 7, extra: None }), unknown: false, exit_code: 101 }
error: [7] Couldn't connect to server

Using Wireshark, I determined cargo is ignoring the non-default port (8081 in this example) during the artifact upload phase and instead is attempting to upload to the repository using a default port (80), and this fails as one would expect. Wireshark connection that fails is shown below:

56    4.045290    127.0.0.1    127.0.0.1    TCP    44    80 → 57759 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0

When running Cargo on Windows, the native OS implementation is used - libgit2 uses a Window's API for connecting instead of the built-in stuff.

When running on non-Windows OS, there was a bug in libgit2 that sends the Server header without a port. This was fixed a while back: libgit2/libgit2@4ef2b88.
cargo uses the git2 crate (https://github.com/rust-lang/git2-rs) which builds libgit2 from a specific commit that is before the above fix. That issue has been reported here: rust-lang/git2-rs#405

I wanted to submit a bug here as well to ensure a fix makes it into cargo.

Possible Solution(s)
Integrate the above fix into cargo

Notes

Output of cargo version:
cargo 1.32.0 (8610973 2019-01-02)
and locally built:
cargo 1.34.0

As mentioned above, the issue with ignoring non-default registry port only occurs on non-Windows OS.

[sfackler]

cargo publish doesn't directly edit the index. It just uploads the crate and some metadata to the registry server.

[mx-shift]

Because Nexus can be behind a reverse-proxy, it uses the Host header to determine its user-visible hostname and port. When cargo clones the index repo, libgit2 sends a Host header that omits the port. Nexus uses that header to construct the API and download urls in config.json. If Nexus is on a non-default port, the publish API gets sent to port 80. The bug in libgit2 was fixed in November. Libgit2-sys is pinned to a version from last March. Updating libgit2-sys will resolve the problem.

[bhamail]

ping. Anything I can do to help move this along?

[ehuss]

I believe this is now fixed via #7018 (or maybe #7176).
cc rust-lang/git2-rs#405