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-supply-chain, a cargo subcommand to gather author, contributor and publisher data on crates in your dependency graph.

Despite a lack of nominations, llogiq is pleased with his choice.

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

341 pull requests were merged in the last week

Rust Compiler Performance Triage

It was a somewhat quiet week with real-world benchmarks showing a slight improvement on average and only one real-world crate, bitmaps, experiencing regressions. Unfortunately, the cause of the regressions don't look straightforward though. The biggest performance win came from a change to not encode attributes in metadata that are only used within the local crate. This improved doc builds of 16 of the 18 real world crates we run in our performance suite!

Triage done by @rylev. Revision range: c51871..7355d


Regressions 😿
Regressions 😿
Improvements 🎉
Improvements 🎉
All 😿 🎉
count 7 9 40 43 47
mean 1.6% 2.6% -0.6% -1.3% -0.3%
max 1.9% 3.5% -2.6% -2.6% -2.6%

2 Regressions, 4 Improvements, 0 Mixed; 0 of them in rollups 51 artifact comparisons made in total

See the full report for more.

Call for Testing (New!)

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:

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.


Tracking Issues & PRs

New and Updated RFCs

Upcoming Events

Rusty Events between 2022-05-18 - 2022-06-15 🦀


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Rust Jobs






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Quote of the Week

It is worth remembering that there is an infinitely large set of programs but a very small set of useful programs. A programming language is a form of ad-hoc compression algorithm, it is intended to sort the set of useful programs to have shorter encodings than the undesirable ones. Programs with certain categories of error or security vulnerability should be harder or impossible to express.

david_chisnall on lobste.rs

Thanks to Anton Fetisov 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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