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 X (formerly 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.

Want TWIR in your inbox? Subscribe here.

Updates from Rust Community

Foundation

• 2024 in Review: Rust Foundation Annual Report Preview

Project/Tooling Updates

• Announcing axum 0.8.0
• Fish 4.0: The Fish Of Theseus
• Rust and libcosmic in Bottles Next
• gitlab-tokens-exporter 1.0.0 - Exports the status of gitlab tokens as Prometheus metrics
• Danube pub/sub messaging platform - updates v0.2.0

Observations/Thoughts

• Catching up with async Rust
• [audio] Reliable software: An interview with Jon Gjengset
• [audio] Rust in Google with Lars Bergstrom
• [video] 12 months with the Bevy Game Engine - This Year in Bevy 2024

Rust Walkthroughs

• A Complete Guide to WASIp2 for Rust and Python Programmers

Crate of the Week

This week's crate is fake, a library (and recently console utility) to generate fake data of various types.

Thanks to llogiq for the half-self-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. The following RFCs would benefit from user testing before moving forward:

RFCs

• No calls for testing were issued this week.

Rust

• No calls for testing were issued this week.

Rustup

• No calls for testing were issued 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.

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.

• clearscreen - Refactor winapi usage to windows-sys

• rama - support HAR exporter (http) layer in rama
• rama - add full-stack rama benchmarks

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 X (formerly Twitter) 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.

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 X (formerly Twitter) or Mastodon!

Updates from the Rust Project

331 pull requests were merged in the last week

• enable LSX feature for LoongArch OpenHarmony target
• explicitly set float ABI for all ARM targets
• A couple datalog/borrowck cleanups
• rustc_codegen_ssa: Buffer file writes in link_rlib
• account for C string literals and format_args in HiddenUnicodeCodepoints lint
• account for removal of multiline span in suggestion
• actually print all the relevant parts of a coroutine in verbose mode
• add --no-capture/--nocapture as bootstrap arguments
• add a compiler intrinsic to back bigint_helper_methods
• avoid ICE in borrowck
• compiler: add a statement-of-intent to rustc_abi
• compute liveness constraints in location-sensitive polonius
• consider arm to diverge if guard diverges
• consider empty-unreachable otherwise branches in MatchBranchSimplification
• default to short backtraces for dev builds of rustc itself
• implement default_overrides_default_fields lint
• improve default target options for x86_64-unknown-linux-none
• improve type mutation for certain structures
• make -Csoft-float have an effect on all ARM targets
• make ty::Error implement all auto traits
• make sure we check the future type is Sized in AsyncFn*
• skip parenthesis around tuple struct field calls
• skip parenthesis if . makes statement boundary unambiguous
• some random region tweaks
• strip debuginfo from rustc-main and rustdoc
• miri: FD handling: avoid unnecessary dynamic downcasts
• miri: epoll: avoid some clones
• miri: error on some invalid flag combinations
• miri: fix toolchain flag parsing
• miri: socket read/write cleanup
• stabilize const_alloc_layout
• stabilize const_swap
• stabilize style_edition = "2024" in-tree
• make slice::as_flattened_mut unstably const
• tidy up bigint multiplication methods
• from iterator for more tuples
• add into_array conversion destructors for Box, Rc, and Arc
• avoid short writes in LineWriter
• unify fs::copy and io::copy on Linux
• fix forgetting to save statx availability on success
• fix mistake in windows file open
• fix renaming symlinks on Windows
• windows: use WriteFile to write to a UTF-8 console
• windows: use FILE_ALLOCATION_INFO for truncation
• cargo: fix(package): check dirtiness of path fields in manifest
• cargo: fix(package): check dirtiness of symlinks source files
• cargo: fix(package): warn if symlinks checked out as plain text files
• cargo: refactor(package): split cargo_package to modules
• cargo: fix: assure possibly blocking non-files (like FIFOs) won't be picked up for publishing
• cargo: moved manifest metadata tracking from fingerprint to dep info
• cargo: test: make path arguments more generic and flexible
• cargo: test: relax bad_crate_type to only match error message prefix
• cargo: test: relax panic output assertion
• rustdoc: use shorter paths as preferred canonical paths
• unsafe binder support in rustdoc
• clippy: borrow_interior_mutable_const ICE into FN
• clippy: auto-fix if_not_else
• clippy: correct suggestion for manual_div_ceil lint
• clippy: do not remove required parentheses in borrow_as_ptr suggestion
• clippy: do not trigger trailing_empty_array in tests
• clippy: fix arguments of ExprKind::MethodCall
• clippy: fix parentheses when replacing matches!(…, None) with .is_none()
• clippy: make inconsistent_struct_constructor "all fields are shorthand" requirement configurable
• clippy: remove description of known problems in match_same_arms that have already been resolved
• clippy: remove obsolete comment
• clippy: use the correct ParamEnv when checking future's output type
• clippy: use the full lifetime name in suggestions
• rust-analyzer: cleanup target fetching for cargo metadata
• rust-analyzer: cleanup toolchain info fetching
• rust-analyzer: decouple proc-macro server protocol from the server implementation
• rust-analyzer: show go-to-type-def actions for subst when hovering
• rust-analyzer: show substitution where hovering over generic things
• rust-analyzer: unify handling of path diagnostics in hir-ty
• rust-analyzer: fix bug of "fill match arm" action in tokio::main macro
• rust-analyzer: fix missing name enum when hovering on fields in variants
• rust-analyzer: fix render of literal to be rendered in codeblock
• rust-analyzer: fix replace-if-let-with-match generates non-exhausive match
• rust-analyzer: avoid generating colliding names in extract_variable
• rust-analyzer: consider Enum::Variant even when it comes from a different crate
• rust-analyzer: do not merge spans if they have different anchors
• rust-analyzer: fix flycheck diagnostics flickering for binary targets
• rust-analyzer: fix invalid -O flag used by cfg discovery
• rust-analyzer: fix metrics workflow using the wrong download-artifact version
• rust-analyzer: incorrect file_id used for ranges in outgoing calls
• rust-analyzer: populate cargo config env vars for crates
• rust-analyzer: implement parameter variance inference
• rust-analyzer: treat ; as a terminator rather part of a glued expression

Rust Compiler Performance Triage

A pretty quiet week, with the exception of a significant improvement due to landing LTO for C / C++ programs compiled as part of the build.

Triage done by @simulacrum. Revision range: 0eca4dd3..93722f7e

0 Regressions, 1 Improvements, 1 Mixed; 0 of them in rollups 53 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.

RFCs

• No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

Rust

• No RFCs entered Final Comment Period this week.

Cargo

• No Cargo Tracking Issues or PRs entered Final Comment Period this week.

Language Team

• No Language Team Proposals entered Final Comment Period this week.

Language Reference

• No Language Reference RFCs entered Final Comment Period this week.

Unsafe Code Guidelines

• No Unsafe Code Guideline Tracking Issues or PRs entered Final Comment Period this week.

New and Updated RFCs

• [new] RFC: Foo { .. } pattern matches non-struct types
• [new] RFC: add LLM text version to rustdoc
• [new] RFC: cfg_os_version_min

Upcoming Events

Rusty Events between 2025-01-01 - 2025-01-29 🦀

Virtual

• 2025-01-02 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2025-01-04 | Virtual (Kampala, UG) | Rust Circle Kampala
  • Rust Circle Meetup
• 2025-01-08 | Virtual (Tel Aviv-Yafo, IL) | Code Mavens 🦀 - 🐍 - 🐪
  • BlockMesh Network implemented in Rust with Ohad Dahan (Virtual, English)
• 2025-01-09 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2025-01-09 | Miami, FL, US | Rust Miami
  • Rust / Wasm on Serverless and Frontend
• 2025-01-09 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2025-01-14 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Second Tuesday
• 2025-01-15 | Virtual (Tel Aviv-Yafo, IL) | Code Mavens 🦀 - 🐍 - 🐪
  • An introduction to WASM in Rust with Márk Tolmács (Virtual, English)
• 2025-01-15 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Leptos
• 2025-01-16 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2025-01-21 | Virtual (Tel Aviv-Yafo, IL) | Rust 🦀 TLV
  • Exploring Rust Enums with Yoni Peleg (Virtual, Hebrew)
• 2025-01-21 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2025-01-22 | Virtual (Rotterdam, NL) | Bevy Game Development
  • Bevy Meetup #8
• 2025-01-26 | Virtual (Tel Aviv-Yafo, IL) | Rust 🦀 TLV
  • Rust and embedded programming with Leon Vak (online in Hebrew)

Asia

• 2025-01-12 | Virtual (Tel Aviv-Yafo, IL) | Rust 🦀 TLV
  • In person Rust January 2025 at Abra in Raanana

Europe

• 2025-01-08 | Girona, ES | Rust Girona
  • Rust Girona - 2025 01
• 2025-01-08 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup
• 2025-01-09 | Oslo, NO | Rust Oslo
  • Rust Hack'n'Learn at Kampen Bistro
• 2025-01-14 | Mannheim, DE | Hackschool - Rhein-Neckar
  • Rust Your Engines #5
• 2025-01-16 | Amsterdam, NL | Rust Developers Amsterdam Group
  • Meetup @ Avalor AI
• 2025-01-16 | Karlsruhe, DE | Rust Hack & Learn Karlsruhe
  • Karlsruhe Rust Hack and Learn Meetup bei BlueYonder
• 2025-01-21 | Ghent, BE | Systems Programming Ghent
  • Tech Talks & Dinner: Insights on Systems Programming Side Projects (in Rust) - Leptos (full-stack Rust with webassembly), Karyon (distributed p2p software in Rust), FunDSP (audio synthesis in Rust)
• 2025-01-21 | Leipzig, SN, DE | Rust - Modern Systems Programming in Leipzig
  • Self-Organized Peer-to-Peer Networks using Rust
• 2025-01-23 | Barcelona, ES | Barcelona Free Software
  • Why Build a New Browser Engine in Rust?
• 2025-01-28 | Aarhus, DK | Rust Aarhus
  • Hack Night - Advent of Code

North America

• 2025-01-08 | Austin, TX, US | Rust ATX
  • Rust Dinner - Pinthouse Pizza South Lamar
• 2025-01-09 | Mountain View, CA, US | Hacker Dojo
  • RUST MEETUP at HACKER DOJO
• 2025-01-10 | Boston, MA, US | Boston Rust Meetup
  • Lechmere Rust Lunch, Jan 10
• 2025-01-16 | Nashville, TN, US | Music City Rust Developers
  • Rust Game Development Series 1: Community Introductions
• 2025-01-18 | Boston, MA, US | Boston Rust Meetup
  • Back Bay Rust Lunch, Jan 18
• 2025-01-21 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2025-01-22 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground

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

Hear, hear! Rust is the real deep state. They knew all along that memory-related bugs would dominate the Vulnerability Rating Taxonomy. Coincidence? I think not. 🐛🔧

– @amoghavarsha@infosec.exchange on mastodon

Thanks to llogiq for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, cdmistman, ericseppanen, extrawurst, U007D, joelmarcey, mariannegoldin, bennyvasquez, bdillo Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust