Issue Tracker

Cargo’s issue tracker is located at This is the primary spot where we track bugs and small feature requests. See Process for more about our process for proposing changes.

Filing issues

We can’t fix what we don’t know about, so please report problems liberally. This includes problems with understanding the documentation, unhelpful error messages, and unexpected behavior.

If you think that you have identified an issue with Cargo that might compromise its users’ security, please do not open a public issue on GitHub. Instead, we ask you to refer to Rust’s security policy.

Opening an issue is as easy as following this link. There are several templates for different issue kinds, but if none of them fit your issue, don’t hesitate to modify one of the templates, or click the Open a blank issue link.

The Rust tools are spread across multiple repositories in the Rust organization. It may not always be clear where to file an issue. No worries! If you file in the wrong tracker, someone will either transfer it to the correct one or ask you to move it. Some other repositories that may be relevant are:

Issues with cargo fix can be tricky to know where they should be filed, since the fixes are driven by rustc, and the front-interface is implemented in Cargo. Feel free to file in the Cargo issue tracker, and it will get moved to the rust-lang/rust issue tracker if necessary.

Issue labels

Issue labels are very helpful to identify the types of issues and which category they are related to.

Anyone can apply most labels by posting comments with a form such as:

@rustbot label: +A-doctests, -A-dependency-resolution

This example will add the A-doctests label and remove the A-dependency-resolution label.

The labels use a naming convention with short prefixes and colors to indicate the kind of label:

A- YellowThe area of the project an issue relates to.
beta- Dark BlueTracks changes which need to be backported to beta
C- Light PurpleThe category of an issue.
Command- Dark PurpleThe cargo command it is related to.
E- GreenThe experience level necessary to fix an issue.
I- RedThe importance of the issue.
O- Purple GreyThe operating system or platform that the issue is specific to.
P- OrangeThe issue priority.
regression- PinkTracks regressions from a stable release.
relnotes Light OrangeMarks issues or PRs that should be highlighted in the Rust release notes of the next release.
S-VariesTracks the status of issues and pull requests (see Issue status labels)
Z- Dark BlueUnstable, nightly features.

Issue status labels

The S- prefixed status labels are the primary mechanism we use to track what is happening with an issue and what it is waiting on. The following is a list of the status labels and what they mean. This is listed roughly in the order that an issue might go through, though issues will often jump to different steps, or in rare cases have multiple statuses.

  • S-triage — New issues get this label automatically assigned to them to indicate that nobody has yet looked at them, and they need someone to assign other labels and decide what the next step is.

  • S-needs-info — Needs more info, such as a reproduction or more background for a feature request.

    Anyone is welcome to help with providing additional info to help reproduce or provide more detail on use cases and such. But usually this is a request to the initial author.

    When adding this label, there should also usually be a comment that goes along with it stating the information requested.

  • S-needs-team-input — Needs input from team on whether/how to proceed.

    Here it is essentially blocked waiting for a team member to move it to the next stage.

  • S-needs-design — Needs someone to work further on the design for the feature or fix.

    Anyone is welcome to help at this stage, but it should be clear that it is not yet accepted. It is expected that people should contribute comments and ideas to the issue which furthers the process of fleshing out what is needed, or alternate ideas. This may also require reaching out to the wider community via forums and such.

  • S-needs-rfc — Needs an RFC before this can make more progress.

    Anyone is welcome to help at this stage, but it should be clear that it is not yet accepted. However, this should only be tagged for changes that are somewhat likely to be accepted.

  • S-needs-mentor — Needs a Cargo team member to commit to helping and reviewing.

    This is for something that is accepted, such as after an RFC or a team discussion, or an obvious issue that just needs fixing, but no team member is available to help or review.

  • S-accepted — Issue or feature is accepted, and has a team member available to help mentor or review.

  • S-waiting-on-feedback — An implemented feature is waiting on community feedback for bugs or design concerns.

    This is typically used on a tracking issue after it has been implemented to indicate what it is waiting on.

Triaging issues

Triaging issues involves processing issues to assign appropriate labels, make sure the issue has sufficient information, and to decide the next steps. When new issues are filed, they should automatically get the S-triage label assuming the author uses one of the templates. This helps identify which issues have not yet been triaged.

There are several things to consider when triaging an issue:

  • Is this a duplicate? Search the issue tracker (including closed issues) to see if there is something similar or identical to what is reported. If it is obviously a duplicate, write a comment that it is a duplicate of the other issue, and close the issue. If it isn’t obvious that it is a duplicate, leave a comment asking the author if the other issue covers what they reported.

  • For a bug, check if the report contains enough information to reproduce it. If you can’t reproduce it, solicit more information from the author to better understand the issue. Change the label from S-triage to S-needs-info if this is the case.

  • Add labels that describe what the issue is related to.

    • Add the appropriate A-, Command-, O-, and Z- prefixed labels.
    • If this is a regression from stable, add one of the regression- prefixed labels (depending on if it is a regression in an already released stable release, or it is in nightly).
  • Assuming the issue looks valid, remove the S-triage label and move it onto a new status:

    • S-needs-rfc — This is a large feature request that will require a public design process.
    • S-needs-design — The resolution of the issue or small feature request will need more work to come up with the appropriate design.
    • S-needs-team-input — The next steps are not clear, and the Cargo team needs to discuss whether or not to proceed and what needs to be done to address the issue.
    • S-needs-mentor — This is something the Cargo team wants to address, but does not currently have the capacity to help with reviewing.
    • S-accepted — This is something that clearly needs to be addressed, and a Cargo team member has volunteered to help review.

Anyone is welcome to help with the triaging process. You can help with reproducing issues, checking for duplicates, gathering more information from the reporter, assigning labels using @rustbot comments, and creating a test using Cargo’s testsuite (example).