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? Tweet us at @ThisWeekInRust or send us a pull request. Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub. 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 cargo-semver-checks, a CI-friendly tool to check your library's API.

Thanks to Predrag Gruevski and Matthias Beyer for the (self and other) nominations.

Please submit your suggestions and votes for next week!

Call for Participation

Always wanted to contribute to open-source projects but didn't 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

397 pull requests were merged in the last week

Rust Compiler Performance Triage

Overall it was a mostly good week, with some very significant wins among the secondary benchmarks. Rollups continue to complicate triage process.

Triage done by @pnkfelix. Revision range: 8bd12e8c..50166d5e


mean max count
Regressions 😿
N/A N/A 0
Regressions 😿
2.2% 3.2% 6
Improvements 🎉
-1.8% -21.2% 199
Improvements 🎉
-2.6% -9.0% 124
All 😿🎉 (primary) -1.8% -21.2% 199

5 Regressions, 4 Improvements, 4 Mixed; 4 of them in rollups 61 artifact comparisons made in total

Full report here

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.

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.


  • No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

New and Updated RFCs

Upcoming Events

Rusty Events between 2022-07-27 - 2022-08-24 🦀




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

JuSt Be CaReFuL

If there’s one lesson from decades of software engineering, it is the failure of “just be careful” as a strategy. C/C++ programmers still experience memory corruption constantly, no matter how careful they are. Java programmers still frequently see NullPointerExceptions, no matter how careful they are. And so on. One of the reasons that Rust is so successful is that it adds automated checks to prevent many common mistakes.

Robert Grosse on their blog

Thanks to robin 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.

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Discuss on r/rust