Sean McArthur
@seanmonstar.com
Open Source maintainer of the rust-lang @hyper.rs.
More at seanmonstar.com
More at seanmonstar.com
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Sean McArthur
@seanmonstar.com
· Jun 23
Owning my microblog with POSSE
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
Reading LLM text makes us worse writers
Originally at https://seanmonstar.com/micro/20260917-reading-llms-worsens-writing/
Originally at https://seanmonstar.com/micro/20260917-reading-llms-worsens-writing/
Reading LLM text makes us worse writers
The top advice given to anyone wanting to get better at writing, besides just writing, is to _read_ more. Especially good writing. Because we imitate that which we experience more of.
seanmonstar.com
September 17, 2026 at 4:22 PM
Reading LLM text makes us worse writers
Originally at https://seanmonstar.com/micro/20260917-reading-llms-worsens-writing/
Originally at https://seanmonstar.com/micro/20260917-reading-llms-worsens-writing/
Reposted by Sean McArthur
What comes after git
Our thoughts about the future of version control
ersc.io
September 10, 2026 at 5:43 PM
Reposted by Sean McArthur
rustls, our modern memory-safe TLS implementation is 10 years old! @jbp.io wrote a blog post reflecting on how we got here:
rustls.dev/blog/2026-09...
rustls.dev/blog/2026-09...
rustls: A Decade of Rustls
rustls.dev
September 9, 2026 at 10:13 AM
rustls, our modern memory-safe TLS implementation is 10 years old! @jbp.io wrote a blog post reflecting on how we got here:
rustls.dev/blog/2026-09...
rustls.dev/blog/2026-09...
Reposted by Sean McArthur
Welcoming Jess Izen as our new Engineer in Residence! For the next year she'll work with our team (while staying at AWS) on crates.io security and support for #rustlang community libraries, starting with malicious crate detection for new publishes! 🦀 Learn more: rustfoundation.org/media/welcom...
August 27, 2026 at 4:51 PM
Welcoming Jess Izen as our new Engineer in Residence! For the next year she'll work with our team (while staying at AWS) on crates.io security and support for #rustlang community libraries, starting with malicious crate detection for new publishes! 🦀 Learn more: rustfoundation.org/media/welcom...
Using LLMs to find not-that-rock
Originally at https://seanmonstar.com/micro/20260825-llms-not-that-rock/
Originally at https://seanmonstar.com/micro/20260825-llms-not-that-rock/
Using LLMs to find not-that-rock
Imagine someone tells you to get them a rock. You go find one, bring it back, and they reply 'no, not that rock'. They didn't know exactly what they wanted, but they knew yours wasn't it.
seanmonstar.com
August 25, 2026 at 2:14 PM
Using LLMs to find not-that-rock
Originally at https://seanmonstar.com/micro/20260825-llms-not-that-rock/
Originally at https://seanmonstar.com/micro/20260825-llms-not-that-rock/
Reposted by Sean McArthur
New blog post: Tending my little plot of the internet
Basically, the subscribe-via-email is much better, and there is now a self-hosted microblog.
seanmonstar.com/blog/owning-...
Basically, the subscribe-via-email is much better, and there is now a self-hosted microblog.
seanmonstar.com/blog/owning-...
Tending my little plot of the Internet
As many parts of the Internet continue to get worse, I figured it was time to improve my own little plot.
seanmonstar.com
August 17, 2026 at 8:05 PM
New blog post: Tending my little plot of the internet
Basically, the subscribe-via-email is much better, and there is now a self-hosted microblog.
seanmonstar.com/blog/owning-...
Basically, the subscribe-via-email is much better, and there is now a self-hosted microblog.
seanmonstar.com/blog/owning-...
New #rustlang h2 release v0.4.16 out today!
- Enforce limits on tiny DATA frames. (GHSA-q83h-524g-xf6h)
- Significant performance improvements: IO contention and HPACK decoding.
- Several smaller fixes.
Worth an upgrade!
github.com/hyperium/h2/...
- Enforce limits on tiny DATA frames. (GHSA-q83h-524g-xf6h)
- Significant performance improvements: IO contention and HPACK decoding.
- Several smaller fixes.
Worth an upgrade!
github.com/hyperium/h2/...
Release v0.4.16 · hyperium/h2
What's Changed fix: error instead of busy-looping when write returns Ok(0) by @ArniDagur in #921 Revert "perf(header): optimize HeaderValue creation via zero-copy sharing" by @0x676e67 in #924 fix...
github.com
August 17, 2026 at 4:33 PM
New #rustlang h2 release v0.4.16 out today!
- Enforce limits on tiny DATA frames. (GHSA-q83h-524g-xf6h)
- Significant performance improvements: IO contention and HPACK decoding.
- Several smaller fixes.
Worth an upgrade!
github.com/hyperium/h2/...
- Enforce limits on tiny DATA frames. (GHSA-q83h-524g-xf6h)
- Significant performance improvements: IO contention and HPACK decoding.
- Several smaller fixes.
Worth an upgrade!
github.com/hyperium/h2/...
Reposted by Sean McArthur
Rust CI now runs cargo-semver-checks to prevent accidental breakage in the standard library 🦀
If you're wondering why that's important and why it took 15kLoC+, this post is for you.
predr.ag/blog/protect...
If you're wondering why that's important and why it took 15kLoC+, this post is for you.
predr.ag/blog/protect...
Protecting the Rust standard library from accidental breakage
How & why we're running cargo-semver-checks in Rust's CI
predr.ag
August 16, 2026 at 2:13 PM
Rust CI now runs cargo-semver-checks to prevent accidental breakage in the standard library 🦀
If you're wondering why that's important and why it took 15kLoC+, this post is for you.
predr.ag/blog/protect...
If you're wondering why that's important and why it took 15kLoC+, this post is for you.
predr.ag/blog/protect...
A trait for fluent Durations
Originally at https://seanmonstar.com/micro/20260812-trait-fluent-durations/
Originally at https://seanmonstar.com/micro/20260812-trait-fluent-durations/
A trait for fluent Durations
I dislike the pattern in some languages to create durations by multiplying constants. It feels like a concession when it cannot be expressed more nicely. There's a tracking issue (https://triagebot.infra.rust-lang.org/gh-comments/rust-lang/rust/issues/57391) to add such constants in libstd.
seanmonstar.com
August 12, 2026 at 2:51 PM
A trait for fluent Durations
Originally at https://seanmonstar.com/micro/20260812-trait-fluent-durations/
Originally at https://seanmonstar.com/micro/20260812-trait-fluent-durations/
Reposted by Sean McArthur
New #rustlang http v1.5.0 out now!
Support for the new `QUERY` method from RFC 10008!
And of course bug fixes.
github.com/hyperium/htt...
Support for the new `QUERY` method from RFC 10008!
And of course bug fixes.
github.com/hyperium/htt...
Release v1.5.0 · hyperium/http
What's Changed feat(method): add QUERY method by @seanmonstar in #798 fix(uri): allow empty paths in uri::Builder by @seanmonstar in #853 perf(header,uri): faster value validation, URI parse/forma...
github.com
July 29, 2026 at 3:00 PM
New #rustlang http v1.5.0 out now!
Support for the new `QUERY` method from RFC 10008!
And of course bug fixes.
github.com/hyperium/htt...
Support for the new `QUERY` method from RFC 10008!
And of course bug fixes.
github.com/hyperium/htt...
Do you ever write a sentence and send it, and then read it back to yourself and think, "oh no, I'm an LLM".
July 23, 2026 at 2:03 PM
Do you ever write a sentence and send it, and then read it back to yourself and think, "oh no, I'm an LLM".
Reposted by Sean McArthur
Three years ago, trying to use Rust for web apps was crazy talk. Today is very different than three years ago. Announcing Topcoat, a batteries-included Rust framework for building reactive web applications: tokio.rs/blog/2026-07...
Announcing Topcoat: a framework for building full-stack reactive web apps with Rust | Tokio - An asynchronous Rust runtime
Tokio is a runtime for writing reliable asynchronous applications with Rust. It provides async I/O, networking, scheduling, timers, and more.
tokio.rs
July 22, 2026 at 4:29 PM
Three years ago, trying to use Rust for web apps was crazy talk. Today is very different than three years ago. Announcing Topcoat, a batteries-included Rust framework for building reactive web applications: tokio.rs/blog/2026-07...
Accessors can reveal internal representation
Originally at https://seanmonstar.com/micro/20260721-accessors-reveal-internal-repr/
Originally at https://seanmonstar.com/micro/20260721-accessors-reveal-internal-repr/
July 21, 2026 at 3:00 PM
Accessors can reveal internal representation
Originally at https://seanmonstar.com/micro/20260721-accessors-reveal-internal-repr/
Originally at https://seanmonstar.com/micro/20260721-accessors-reveal-internal-repr/
New release of #rustlang hyper out today, v1.11.0! 🚀
Several big bug fixes.
- Buffered data fully flushes even when half closed
- Enforce backpressure in HTTP/2 Upgraded bodies (like CONNECT)
- Start of a strict Clippy allowlist
- 10 contributors, 7 of them new! 🦀
github.com/hyperium/hyp...
Several big bug fixes.
- Buffered data fully flushes even when half closed
- Enforce backpressure in HTTP/2 Upgraded bodies (like CONNECT)
- Start of a strict Clippy allowlist
- 10 contributors, 7 of them new! 🦀
github.com/hyperium/hyp...
Release v1.11.0 · hyperium/hyper
Features rt: add ReadBufCursor::initialized_unfilled() method (#4115) (ccc1e850) Bug Fixes http1: discard content-length header when received before transfer-encoding (#4124) (540fff91, closes ...
github.com
July 20, 2026 at 2:07 PM
New release of #rustlang hyper out today, v1.11.0! 🚀
Several big bug fixes.
- Buffered data fully flushes even when half closed
- Enforce backpressure in HTTP/2 Upgraded bodies (like CONNECT)
- Start of a strict Clippy allowlist
- 10 contributors, 7 of them new! 🦀
github.com/hyperium/hyp...
Several big bug fixes.
- Buffered data fully flushes even when half closed
- Enforce backpressure in HTTP/2 Upgraded bodies (like CONNECT)
- Start of a strict Clippy allowlist
- 10 contributors, 7 of them new! 🦀
github.com/hyperium/hyp...
Rust Errors generally shouldn't be PartialEq
Originally at https://seanmonstar.com/micro/20260713-errors-not-partialeq/
Originally at https://seanmonstar.com/micro/20260713-errors-not-partialeq/
July 13, 2026 at 6:27 PM
Rust Errors generally shouldn't be PartialEq
Originally at https://seanmonstar.com/micro/20260713-errors-not-partialeq/
Originally at https://seanmonstar.com/micro/20260713-errors-not-partialeq/
Reposted by Sean McArthur
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2?
It would be a big help! github.com/hyperium/h2/...
It would be a big help! github.com/hyperium/h2/...
Refactor big mutex to reduce contention by seanmonstar · Pull Request #917 · hyperium/h2
This refactor puts the big internal shared mutex on a diet. The goal is to reduce contention, providing performance improvements when h2 is used on multi-threaded runtimes. WarningThis is a large i...
github.com
June 30, 2026 at 1:06 PM
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2?
It would be a big help! github.com/hyperium/h2/...
It would be a big help! github.com/hyperium/h2/...
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2?
It would be a big help! github.com/hyperium/h2/...
It would be a big help! github.com/hyperium/h2/...
Refactor big mutex to reduce contention by seanmonstar · Pull Request #917 · hyperium/h2
This refactor puts the big internal shared mutex on a diet. The goal is to reduce contention, providing performance improvements when h2 is used on multi-threaded runtimes. WarningThis is a large i...
github.com
June 30, 2026 at 1:06 PM
Do you use #rustlang hyper/h2 at scale? Would you be able to easily try out a performance run using a PR that is meant to significantly reduce contention with multi-threaded HTTP/2?
It would be a big help! github.com/hyperium/h2/...
It would be a big help! github.com/hyperium/h2/...
Reposted by Sean McArthur
[NEWS] The Rust Foundation has launched the Rust Commercial Network: a free, open community for orgs building Rust in production to collaborate & share real-world use-cases with the Rust Project. Founding members span big tech, Rust specialists, & community orgs.
rustfoundation.org/media/rust-c...
rustfoundation.org/media/rust-c...
June 24, 2026 at 4:55 PM
[NEWS] The Rust Foundation has launched the Rust Commercial Network: a free, open community for orgs building Rust in production to collaborate & share real-world use-cases with the Rust Project. Founding members span big tech, Rust specialists, & community orgs.
rustfoundation.org/media/rust-c...
rustfoundation.org/media/rust-c...
Owning my microblog with POSSE
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
June 23, 2026 at 3:16 PM
Owning my microblog with POSSE
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
Originally at https://seanmonstar.com/micro/2026/06/23/owning-my-microblog-with-posse/
New #rustlang h2 v0.4.15 out now! 🚀
Includes several bug fixes for capacity, resets, and more.
github.com/hyperium/h2/...
Includes several bug fixes for capacity, resets, and more.
github.com/hyperium/h2/...
Release v0.4.15 · hyperium/h2
What's Changed fix: Discard buffered DATA when a scheduled reset is pending by @ArniDagur in #896 fix: poll_capacity must not return Ready(Some(Ok(0))) by @ArniDagur in #898 fix: Reject frames on ...
github.com
June 15, 2026 at 1:26 PM
New #rustlang h2 v0.4.15 out now! 🚀
Includes several bug fixes for capacity, resets, and more.
github.com/hyperium/h2/...
Includes several bug fixes for capacity, resets, and more.
github.com/hyperium/h2/...
Reposted by Sean McArthur
To put it another way:
if the official position of the Android and Linux kernel teams is “we, some of the world’s best coders, can’t safely use C” then the bar under CRA’s requirements of “safe by design” should be nearly impossible to meet for mere mortals when using C.
if the official position of the Android and Linux kernel teams is “we, some of the world’s best coders, can’t safely use C” then the bar under CRA’s requirements of “safe by design” should be nearly impossible to meet for mere mortals when using C.
June 1, 2026 at 7:34 PM
To put it another way:
if the official position of the Android and Linux kernel teams is “we, some of the world’s best coders, can’t safely use C” then the bar under CRA’s requirements of “safe by design” should be nearly impossible to meet for mere mortals when using C.
if the official position of the Android and Linux kernel teams is “we, some of the world’s best coders, can’t safely use C” then the bar under CRA’s requirements of “safe by design” should be nearly impossible to meet for mere mortals when using C.