fidzu : thunderbird

The latest version of PerfCompare is now live!

Check out the change-log below to see the updates:

[andra - esanuandra ]

• PCF-391 The keyboard handling for the revision dropdown should be done differently (#926)

[david - davidmiculit ]

• Bug 2040649 - Remove Raptor framework from PerfCompare (#1042)

[kala - kala-moz ]

• Results Page: Return the scatter series for base and new back to original order (#1046)

• Bug: 2044194 Port client-side KDE mode detection from kde-widget into CommonGraph (#1045)

• Bug 2034263: Give subtest column in subtest page a max-width (#1047)

[paul - padenot]

• Two small followups on modal-work (#1049)

• Assorted fixes to improve the app when numbers are very large and not measuring time. (#1050)

Thank you for the contributions!

Bugs or feature requests can be filed on Bugzilla. The team can also be found on the #perfcompare channel on Element. Come and chat!

1 post - 1 participant

Read full topic

17 Jun 2026 4:46pm GMT

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.

Want TWIR in your inbox? Subscribe here.

Updates from Rust Community

Project/Tooling Updates

• cuTile Rust - Fearless Concurrency on the GPU, memory-safe, data-race-free GPU kernels, B200 benchmarks
• Iroh 1.0 - Dial Keys, not IPs
• Diplomat - Multi-language FFI for Rust libraries
• I built EVM from scratch. Again.
• processkit 1.0 - async process tree management
• litchee: Rust Lichess API client
• Basin - Numerical Optimization in Rust
• Carboxyl 0.1.0-rc - A servo-based browser for the terminal
• kache 0.6.0 - a shareable Rust + C/C++ build cache
• numax v0.1.0 - first stable release of the numax distributed WASM runtime
• ZamSync - offline-first Rust sync engine
• Ktav - a quote-free config format

Observations/Thoughts

• zlib-rs in Firefox
• Rust Prevents Data Races, Not Race Conditions
• Build your project Zig-style
• How memory safety CVEs differ between Rust and C/C++
• Why stdx is not on crates.io
• [videos] RustWeek 2026 by RustNL, all talks playlist
• The iPad was on Tailscale

Rust Walkthroughs

• Learn Rust Concurrency By Building a Thread Pool
• There Is Life Before Main in Rust
• Async Task Locals From Scratch
• Fearless Embedded Rust: Driving a Lego Car with a Pico W
• Building a provider-agnostic LLM layer in Rust with Rig

Miscellaneous

• [video] RustWeek 2026 talk recordings

Crate of the Week

This week's crate is marser, a parser combinator library with a twist.

Thanks to Arne Code for the 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.

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.

No calls for testing were issued this week by Rust, Cargo, Rustup 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.

• solana-infra-doctor - List exit codes in sol-doctor --help
• solana-infra-doctor - Make the invalid-URL error suggest the expected scheme
• solana-infra-doctor - Add a glossary of RPC readiness terms
• openslate - add unit tests for slugify() in api/src/notes.rs
• openslate - add integration tests for notes CRUD in api/src/notes.rs
• openslate - add integration tests for auth flow in api/src/users.rs
• openslate - add unit tests for build_fts_query() in api/src/search.rs
• openslate - add integration tests for auth middleware and logout in api/src/auth.rs
• openslate - add integration tests for media endpoints (DB layer) in api/src/media.rs
• openslate - add unit tests for ext_from_mime() and filename_from_url() in api/src/media.rs

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.

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

527 pull requests were merged in the last week

Compiler

• obligations_for_self_ty: skip irrelevant goals (recompute sub_root from stalled_vars)
• codegen_ssa: peel trans. wrappers on scalable vecs
• add a check for impossible predicates to trivial_const
• add unstable loop unrolling hint attributes
• improve polymorphization of raw pointer formatting
• introduce #[diagnostic::on_type_error(message)]
• perf: reuse green-marking's edge walk when promoting a node

Library

• add or_try_* variants for HashMap and BTreeMap Entry APIs
• make BorrowedBuf and BorrowedCursor generic over the data
• replace printables table with unicode_data.rs tables
• stabilize #![feature(box_as_ptr)]
• stabilize core::range::{legacy, RangeFull, RangeTo}
• stabilize int_format_into feature
• stabilize nonzero_from_str_radix
• stabilize feature float_algebraic

Cargo

• trim-paths: emit CARGO_TRIM_PATHS_REMAP for build.rs
• diag: Give diagnostics the same display path behavior as rustc
• diag: Report all errors, in order
• publish: avoid false deadlock when to_confirm is non-empty
• resolver: move yank policy to resolver layer

Rustdoc

• also run lint unused_doc_comments
• cleanup and (micro-)optimize print_where_clause
• correct doctest span for trailing semicolon after item
• don't strip hidden items in AliasedNonLocalStripper
• some more lazy formatting

Rustfmt

• add doc_comment_code_block_small_heuristics, to override use_small_heuristics in doc code
• stabilize hex_literal_case

Clippy

• new by_ref_peekable_peek lint
• add with_capacity_zero lint
• mem_replace_with_default: also emit inside macros
• infallible_destructuring_match: clean-up, split off the suggestion from the main message
• manual_is_variant_and: lint result.ok().is_some_and(f)
• needless_borrow: same-name methods false positive
• unnecessary_lazy_evaluations: handle closure ->
• deprecate the from_iter_instead_of_collect lint
• remove is_integer_const
• do not trigger ref_patterns lint on automatically derived code
• enhance never loop
• add profile-specific configuration for disallowed methods and types
• fix collapsible_match suggests wrongly when match body has no braces
• fix unnecessary_sort_by reverse suggestion using wrong closure parameter name
• fix redundant closure call async false positive
• perf: check is_in_test last in incompatible_msrv
• perf: check the token kind before extracting source in early literal lints
• perf: match expression shape before MSRV check in cloned_ref_to_slice_refs
• perf: skip doc_markdown text collection and word scan when the lint is allowed
• perf: skip single_component_path_imports module walk when nothing to lint

Rust-Analyzer

• create directory for cargo xtask metrics rustc_tests
• don't count C-variadic ... as a parameter for fn pointers
• support flyimport exclude variants
• fix destructuring assignments not introducing moves
• offer inline macro in macro call and proc macro
• prefer bench command when target is bench to avoid cargo run
• supports inline variable in macro
• use package id as argument to --package if package is not unique
• assist inline_type_alias work on ADT definitions
• perf: defer initial workspace flycheck until cache priming completes
• remove docs about removed analysis-bench command
• remove unnecessary feature flags from tests
• use ASCII lowercase for dylib extensions check

Rust Compiler Performance Triage

This week we had quite a lot of changes, a few small regressions that were a bit tough to diagnose, but the week is largely positive, overall. Notably, we got one massive improvement on the next-solver benchmark in #156187, and a nice speedup for incremental in #157781.

Triage done by @panstromek. Revision range: f3ef3bd8..b5d46ecb

Summary:

(instructions:u)	mean	range	count
Regressions ❌ (primary)	0.4%	[0.2%, 0.6%]	22
Regressions ❌ (secondary)	0.5%	[0.1%, 2.0%]	40
Improvements ✅ (primary)	-1.8%	[-5.9%, -0.1%]	125
Improvements ✅ (secondary)	-3.8%	[-69.4%, -0.1%]	90
All ❌✅ (primary)	-1.5%	[-5.9%, 0.6%]	147

1 Regression, 4 Improvements, 8 Mixed; 5 of them in rollups 28 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

Rust

• Fix trait method resolution on an adjusted never type
• Tracking Issue for atomic_from_mut
• stabilize never type
• Lint against iterator functions that panic when N is zero

Compiler Team (MCPs only)

• Single-byte counter support in coverage instrumentation
• Rename the compiler files containing struct diagnostics to diagnostics.rs

Leadership Council

• Delegate Project Grants to the Funding team
• Allocate budget to the Funding team

Rust RFCs

• Named Fn trait parameters

Language Reference

• Structs with no fields or all-ZST fields are ZSTs

No Items entered Final Comment Period this week for Cargo, Language Team 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

• No New or Updated RFCs were created this week.

Upcoming Events

Rusty Events between 2026-06-17 - 2026-07-15 🦀

Virtual

• 2026-06-17 | Hybrid (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2026-06-17 | Virtual (Girona, ES) | Rust Girona
  • Weekly coding session
• 2026-06-18 | Hybrid (Seattle, WA, US) | Seattle Rust User Group
  • June, 2026 SRUG (Seattle Rust User Group) Meetup
• 2026-06-18 | Virtual (Berlin, DE) | Rust Berlin
  • Rust Hack and Learn
• 2026-06-21 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Rust Deep Learning: Third Sunday
• 2026-06-23 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Fourth Tuesday
• 2026-06-23 | Virtual (London, UK) | Women in Rust
  • Lunch & Learn: What the heck are monads - and how do we fake them in Rust
• 2026-07-01 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2026-07-02 | Virtual (Berlin, DE) | Rust Berlin
  • Rust Hack and Learn
• 2026-07-02 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Learning Game Development the Hard Way with Rust and Bevy
• 2026-07-02 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2026-07-05 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Rust Deep Learning: First Sunday
• 2026-07-07 | Virtual (London, UK) | Women in Rust
  • 👋 Community Catch Up
• 2026-07-14 | Virtual (Dallas, TX, US) | Dallas Rust User Meetup
  • Second Tuesday
• 2026-07-15 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Jiff

Europe

• 2026-06-18 | Aarhus, DK | Rust Aarhus
  • Talk Night at Danske Commodities
• 2026-06-18 | Edinburgh, GB | Rust and Friends
  • Rust and Friends comes to Glasgow! (daytime coffee)
• 2026-06-18 | Edinburgh, GB | Rust and Friends
  • Rust and Friends comes to Glasgow! (evening pub)
• 2026-06-18 | Barcelona, ES | BcnRust
  • 21st BcnRust Meetup
• 2026-06-19 | Dresden, DE | Rust Dresden
  • Second Meetup
• 2026-06-23 | Paris, FR | Rust Paris
  • Rust meetup #86
• 2026-06-23 | Warsaw, PL | Rust Warsaw
  • Rust Warsaw Meetup: June 2026
• 2026-06-24 | Manchester, GB | Rust Manchester
  • Rust Manchester June Talks
• 2026-06-25 | Berlin, DE | Rust Berlin
  • Rust Berlin Talks: The next generation
• 2026-06-25 | Copenhagen, DK | Copenhagen Rust Community
  • Rust meetup #69
• 2026-07-02 | Edinburgh, GB | Rust and Friends
  • Bevy, Bits, & Cats (Rust July Talks)
• 2026-07-02 | Enschede, OV, NL | Baseflow Tech Meetups
  • AI Summit
• 2026-07-08 | Dublin, IE | Rust Dublin
  • Join us live and INPERSON for Rust 261
• 2026-07-09 | Switzerland, CH | PostTenebrasLab
  • Rust Meetup Geneva

North America

• 2026-06-17 | Hybrid (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2026-06-18 | Hybrid (Seattle, WA, US) | Seattle Rust User Group
  • June, 2026 SRUG (Seattle Rust User Group) Meetup
• 2026-06-18 | Nashville, TN, US | Music City Rust Developers
  • Community Meetup
• 2026-06-20 | Boston, MA, US | Boston Rust Meetup
  • Northeastern Rust Lunch, June 20
• 2026-06-24 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2026-06-24 | Los Angeles, CA, US | Rust Los Angeles
  • Rust LA: Rust-Based Constraint Solvers in 2D Sketching with Zoo Technologies
• 2026-06-25 | Atlanta, GA, US | Rust Atlanta
  • Rust-Atl
• 2026-06-26 | New York, NY, US | Rust NYC
  • Rust NYC's Big Summer Social
• 2026-06-27 | Boston, MA, US | Boston Rust Meetup
  • Somerville Union Square Rust Lunch, June 27
• 2026-07-02 | Saint Louis, MO, US | STL Rust
  • Git is easy?
• 2026-07-04 | Boston, MA, US | Boston Rust Meetup
  • Boston University Rust Lunch, July 4
• 2026-07-09 | Lehi, UT, US | Utah Rust
  • Utah Rust July Meetup
• 2026-07-11 | Boston, MA, US | Boston Rust Meetup
  • MIT Rust Lunch, July 11

Oceania

• 2026-06-25 | Melbourne, AU | Rust Melbourne
  • Rust Melbourne June 2026

South America

• 2026-06-18 | Florianópolis, BR | Rust SC
  • Rust Floripa

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

"The never type is named after the date of its stabilization" was a good joke while it lasted.

- Sergey "Shnatsel" Davidoff on /r/rust

Thanks to Dos Moonen 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

17 Jun 2026 4:00am GMT

WebDriver is a remote control interface that enables introspection and control of user agents. As such, it can help developers to verify that their websites are working and performing well with all major browsers. The protocol is standardized by the W3C and consists of two separate specifications: WebDriver classic (HTTP) and the new WebDriver BiDi (Bi-Directional).

This newsletter gives an overview of the work we've done as part of the Firefox 152 release cycle.

Contributions

Firefox is an open source project, and we are always happy to receive external code contributions to our WebDriver implementation. We want to give special thanks to everyone who filed issues, bugs and submitted patches.

In Firefox 152, multiple WebDriver bugs were fixed by contributors:

• Khalid AlHaddad extended the webExtension.install command to support installing web extensions enabled in Private Browsing mode.
• Sameem improved the Marionette and WebDriver BiDi screenshot commands to enforce maximum allowed dimensions.
• Amin Amir fixed a bug in browsingContext.sys.mjs where a private field was incorrectly assigned without the # prefix.

WebDriver code is written in JavaScript, Python, and Rust so any web developer can contribute! Read how to setup the work environment and check the list of mentored issues for Marionette, or the list of mentored JavaScript bugs for WebDriver BiDi. Join our chatroom if you need any help to get started!

General

• Improved the Marionette and WebDriver BiDi screenshot commands to enforce maximum allowed dimensions.

WebDriver BiDi

• Extended the webExtension.install command to support installing web extensions in Firefox enabled in Private Browsing mode.
• Improved the browser.setDownloadBehavior command to allow overriding the download target folder before the temporary file is created.
• Fixed network events to only forward in-memory cached JavaScript responses when there is a matching network event collector, avoiding unnecessary data forwarding.

Marionette

• Improved the WebDriver:Navigate and WebDriver:Refresh commands to properly report errors when triggering the navigation fails, instead of silently ignoring them.

16 Jun 2026 2:00pm GMT