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.bsky.social on Bluesky 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.

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Updates from Rust Community

Project/Tooling Updates

• reqwest v0.13 - rustls by default
• rama 0.3.0-alpha.4 is released — modular service framework to move and transform network packets
• Ratatui 0.30.0 is released! - a Rust library for cooking up terminal user interfaces

Observations/Thoughts

• Four Years of Rust: An Odyssey of Failures, Achievements, and Hard Lessons
• Simple Bidirectional Type Inference
• serde's borrowing can be treacherous
• Garbage collection in Rust got a little better
• [audio] Netstack.FM episode 20 — Netstack.FM New Year Special, 2025 Wrap-Up

Rust Walkthroughs

• Why is calling my asm function from Rust slower than calling it from C?
• Rust Errors Without Dependencies
• [video] Building your first APP using the new Hotaru Web Framework!

Miscellaneous

• [audio] 2025 Holiday Special - Rust in Production Podcast
• Investigating and fixing a nasty clone bug

Crate of the Week

This week's crate is wgsl-bindgen, a binding generator for WGSL, the WebGPU shading language, to be used with wgpu.

Thanks to Artem Borisovskiy for the suggestion!

Please submit your suggestions and votes for next week!

Calls for Testing

An important step for RFC implementation is for people to experiment with the implementation and give feedback, especially before stabilization.

If you are a feature implementer and would like your RFC to appear in this list, add a 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.

Rustup

• Rustup 1.29.0 beta: Call for Testing!

• Testing steps: See "How to Test" section from above link.

• No calls for testing were issued this week by Rust, Cargo or Rust language RFCs.

Let us know if you would like your feature to be tracked as a part of this list.

Call for Participation; projects and speakers

CFP - Projects

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.

• Spindalis - Create an AST parser
• Spindalis - Add procedural macro for definite integral
• Spindalis - Add a function and macro that can expand polynomials
• Spindalis - Add display trait to functions in spindalis core

If you are a Rust project owner and are looking for contributors, please submit tasks here or through a PR to TWiR or by reaching out on Bluesky or Mastodon!

CFP - Events

Are you a new or experienced speaker looking for a place to share something cool? This section highlights events that are being planned and are accepting submissions to join their event as a speaker.

• RustWeek 2026 | CFP closes 2026-01-18 | Utrecht, The Netherlands | 2026-05-19 - 2026-05-20
• RustConf 2026 | CFP closes 2026-02-16 | Montreal, Quebec, Canada | 2026-09-08 - 2026-09-10

If you are an event organizer hoping to expand the reach of your event, please submit a link to the website through a PR to TWiR or by reaching out on Bluesky or Mastodon!

Updates from the Rust Project

297 pull requests were merged in the last week

Compiler

• recursive delegation improvements
• miri: fix ICE for particular data race situations
• miri: show a warning when combing native-lib mode and many-seeds
• miri: tree Borrows: improve protector end access child skipping

Library

• add MaybeDangling to core
• alloc: specialize String::extend for slices of str
• implement Duration::div_duration_{floor,ceil}
• implement flatten for Option<&Option<T>> and Option<&mut Option<T>>
• optimized implementation for uN::{gather,scatter}_bits
• rewrite String::replace_range
• stabilize lazy_get

Cargo

• index: Stabilize pubtime
• report: new command cargo report sessions
• report: support --manifest-path in cargo report timings
• resolver: List features when no close match
• toml: TOML 1.1 parse support
• vendor: recursively filter git files in subdirectories
• vendor: unpack from local-registry cache path
• build-rs: Reduce from 'build' to 'check' where possible
• experiment: render timing pipeline in SVG
• patch: Display where the patch was defined in patch-related error messages

Rustdoc

• if line number setting is disabled, do not make line numbers take space
• fix copy code example with line numbers
• fix duplicate Re-exports sections
• fix incorrect type filter name in help popup

Clippy

• fix assertions_on_constants false positive when there is non-constant value in the condition expr
• fix double_parens false positive on macro repetition patterns
• fix obfuscated_if_else wrongly unmangled macros
• fix result_large_err false negative on closures
• preserve explicit lifetime information when removing mut
• various fixes for handling of macros

Rust-Analyzer

• add bidirectional messaging proc-macro-srv prototype
• add macro segment completion
• implement configuration to change sub command for test, bench and doctest
• provide a setting to disable showing rename conflicts
• stabilize type mismatch diagnostic 🎉
• indent for convert_to_guarded_return
• fix LSP configuration request handling
• fix parsing of format_args!("...", keyword=...)
• fix type inference when hovering on _
• reenable fixpoint variance
• do not really expand builtin derives, instead treat them specifically
• pre-allocate some buffers in parsing
• reduce channel lock contention for drop-threads
• prompt the user in VSCode to add the rust-anaylzer componenet to the toolchain file

Rust Compiler Performance Triage

Not a lot of changes this week. Overall result is positive, largely thanks to https://github.com/rust-lang/rust/pull/142881, which makes computing an expensive data structure for JumpThreading MIR optimization lazy.

Triage done by @panstromek. Revision range: e1212ea7..112a2742

Summary:

2 Regressions, 0 Improvements, 3 Mixed; 1 of them in rollups 37 artifact comparisons made in total

Full report here

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week: * No RFCs were approved 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

Compiler Team (MCPs only)

• Proposal for a dedicated test suite for the parallel frontend
• Promote tier 3 riscv32 ESP-IDF targets to tier 2
• Proposal for Adapt Stack Protector for Rust
• Give integer literals a sign instead of relying on negation expressions
• Also enable ICE file dumps on stable
• New Tier-3 target proposal: loongarch64-linux-android

No Items entered Final Comment Period this week for Cargo, Rust, Rust RFCs, Leadership Council, Language Team, Language Reference or Unsafe Code Guidelines.

Let us know if you would like your PRs, Tracking Issues or RFCs to be tracked as a part of this list.

New and Updated RFCs

• Thin pointers with inline metadata

Tracking Issues & PRs

New and Updated RFCs

Upcoming Events

Rusty Events between 2025-12-31 - 2026-01-28 🦀

Virtual

• 2026-01-03 | Virtual (Kampala, UG) | Rust Circle Meetup
  • Rust Circle Meetup
• 2026-01-07 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2026-01-08 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Meet, swap, and learn!
• 2026-01-08 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2026-01-13 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Second Tuesday
• 2026-01-13 | Virtual | libp2p Events
  • rust-libp2p Open Maintainers Call
• 2026-01-13 | Virtual (Tel Aviv-yafo, IL) | Code Mavens 🦀 - 🐍 - 🐪
  • Live Open Source Rust project contribution
• 2026-01-14 | Virtual (Girona, ES) | Rust Girona
  • Sessió setmanal de codificació / Weekly coding session
• 2026-01-15 | Virtual (Berlin, DE) | Rust Berlin
  • Rust Hack and Learn
• 2026-01-20 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2026-01-21 | Virtual (Girona, ES) | Rust Girona
  • Sessió setmanal de codificació / Weekly coding session
• 2026-01-21 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Stack Safety
• 2026-01-27 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Fourth Tuesday
• 2026-01-28 | Virtual (Girona, ES) | Rust Girona
  • Sessió setmanal de codificació / Weekly coding session

Asia

• 2026-01-07 | Tel Aviv-yafo, IL | Rust 🦀 TLV
  • In person Rust January 2026 at AWS in Tel Aviv
• 2026-01-08 | Seoul, KR | Seoul Rust (Programming Language) Meetup
  • Seoul Rust Meetup
• 2026-01-17 | Delhi, IN | Rust Delhi
  • Rust Delhi Meetup #12

Europe

• 2026-01-07 | Amsterdam, NL | Rust Developers Amsterdam Group
  • Meetup @ Instruqt
• 2026-01-07 | Girona, ES | Rust Girona
  • Rust Girona Hack & Learn 01 2026
• 2026-01-08 | Geneva, CH | Post Tenebras Lab
  • Rust Meetup Geneva
• 2026-01-14 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup
• 2026-01-20 | Leipzig, SN, DE | Rust - Modern Systems Programming in Leipzig
  • Topic TBD
• 2026-01-20 | Paris, FR | Rust Paris
  • Rust meetup #82

North America

• 2026-01-01 | Saint Louis, MO, US | STL Rust
  • Cancelled
• 2026-01-03 | Boston, MA, US | Boston Rust Meetup
  • Allston Rust Lunch, Jan 3
• 2026-01-08 | Lehi, UT, US | Utah Rust
  • Bringing the data lake to the browser with WASM
• 2026-01-08 | Mountain View, CA, US | Hacker Dojo
  • RUST MEETUP at HACKER DOJO
• 2026-01-10 | Boston, MA, US | Boston Rust Meetup
  • Central Cambridge Rust Lunch, Jan 10
• 2026-01-13 | New York, NY, US | Rust NYC
  • Rust NYC Panel: AI Coding Agents in Rust: What Works, What Breaks
• 2026-01-13 | Spokane, WA, US | Spokane Rust
  • .NET Conference 2025 Spokane
• 2026-01-15 | Seattle, WA, US | Seattle Rust User Group
  • Janurary, 2026 SRUG (Seattle Rust User Group) Meetup
• 2026-01-17 | Boston, MA, US | Boston Rust Meetup
  • Boston Common Rust Lunch, Jan 17
• 2026-01-17 | Herndon, VA, US | NoVaLUG
  • Monthly Meeting - Make Brian Lunduke Angry, Program in Rust
• 2026-01-20 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2026-01-21 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2026-01-22 | Boston, MA, US | Boston Rust Meetup
  • Evening Boston Rust Meetup with Jiff, January 22
• 2026-01-24 | Boston, MA, US | Boston Rust Meetup
  • Davis Square Rust Lunch, Jan 24
• 2026-01-28 | Los Angeles, CA, US | Rust Los Angeles
  • Rust Los Angeles: Building Git-LFS Replacements in Rust

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.

Jobs

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

Quote of the Week

what even is time?!?

– Ralf Jung on his blog

Thanks to llogiq for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by:

• nellshamrell
• llogiq
• ericseppanen
• extrawurst
• U007D
• mariannegoldin
• bdillo
• opeolluwa
• bnchi
• KannanPalani57
• tzilist

Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust