Hello and welcome to another issue of This Week in Rust! Rust is a programming language empowering everyone to build reliable and efficient software. This is a weekly summary of its progress and community. Want something mentioned? Tag us at @ThisWeekInRust on Twitter or @ThisWeekinRust on mastodon.social, or send us a pull request. Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub and archives can be viewed at this-week-in-rust.org. If you find any errors in this week's issue, please submit a PR.

Updates from Rust Community



Project/Tooling Updates


Rust Walkthroughs


Crate of the Week

This week's crate is irsenv, a hierarchical environmant variable manager.

Thanks to sysid for the self-suggestion!

Please submit your suggestions and votes for next week!

Call for Participation

Always wanted to contribute to open-source projects but did not know where to start? Every week we highlight some tasks from the Rust community for you to pick and get started!

Some of these tasks may also have mentors available, visit the task page for more information.

If you are a Rust project owner and are looking for contributors, please submit tasks here.

Updates from the Rust Project

382 pull requests were merged in the last week

Rust Compiler Performance Triage

An interesting week. We saw a massive improvement to instruction-counts across over a hundred benchmarks, thanks to #110050 an improved encoding scheme for the dependency graphs that underlie incremental-compilation. However, these instruction-count improvements did not translate to direct cycle time improvements. We also saw an improvement to our artifact sizes due to #115306. Beyond that, we had a scattering of small regressions to instruction-counts that were justified because they were associated with bug fixes.

Triage done by @pnkfelix. Revision range: 15e52b05..7e0261e7

3 Regressions, 2 Improvements, 5 Mixed; 2 of them in rollups 84 artifact comparisons made in total

Full report

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

Final Comment Period

Every week, the team announces the 'final comment period' for RFCs and key PRs which are reaching a decision. Express your opinions now.


Tracking Issues & PRs

New and Updated RFCs

Call for Testing

An important step for RFC implementation is for people to experiment with the implementation and give feedback, especially before stabilization. The following RFCs would benefit from user testing before moving forward:

  • No RFCs issued a call for testing this week.

If you are a feature implementer and would like your RFC to appear on the above list, add the new call-for-testing label to your RFC along with a comment providing testing instructions and/or guidance on which aspect(s) of the feature need testing.

Upcoming Events

Rusty Events between 2023-09-13 - 2023-10-11 🦀




North America


If you are running a Rust event please add it to the calendar to get it mentioned here. Please remember to add a link to the event too. Email the Rust Community Team for access.


Please see the latest Who's Hiring thread on r/rust

Quote of the Week

It's very much a positive feedback loop: good tooling makes good tooling easier to build, so more of it gets built and the cycle repeats. cargo-semver-checks stands on the shoulders of giants like rustc and rustdoc and Trustfall. Remove any one of them (or even just rustc's high-quality diagnostics!) and cargo-semver-checks wouldn't have been a viable project at all.

Predrag Gruevski on /r/rust

Thanks to Vincent de Phily for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, cdmistman, ericseppanen, extrawurst, andrewpollack, U007D, kolharsam, joelmarcey, mariannegoldin, bennyvasquez.

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