Tweag by Modus Create

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120 Bash exports, a zoo of config formats and crashes minutes into start-up. Simeon Carstens on bringing Nickel, a programmable configuration language written in Rust, to the CodeCommons ingestion pipeline. tweag.io/blog/2026-10... #Nickel #Rust

Final day at #BazelCon 2026! It's been a great few days in Amsterdam, catching up with familiar faces, meeting new ones and chatting all things Bazel. If you're here, there's still time to stop by the Tweag booth and say hello! #Bazel

Missed Guillaume Maudoux’s talk at BazelCon 2026? Guillaume took to the stage yesterday to present “Managing Configurations Explosion 💥” If you missed it, you can catch his talk in the BazelCon livestream on YouTube! Watch here: www.youtube.com/live/mPzunhM... #BazelCon #Bazel

3M+ configured actions. 500k actual actions running. At #BazelCon, Tweag’s Guillaume Maudoux will present “Taming Configurations Explosion,” covering reset transitions, path mapping and option scopes used to reduce configuration redundancy. 14 October | 14:45–15:15 | Room 5–8 #Bazel

Aleksandr Bantev thought running a Nixpkgs team was hard. Turns out it's not! Read about his experience in our latest blog post: www.tweag.io/blog/2026-10... #nix #nixpkgs

Docker builds shouldn’t be the slowest part of CI. At #BazelCon Training Day, Tweag’s Rafael Lima will lead a workshop on using Bazel, rules_oci and rules_img to assemble container images through a graph-based approach, independently of a local Docker daemon. 13 Oct | 09:00–10:30 | Room 11–14

Amsterdam is next. Tweag by Modus Create will be at #BazelCon from 13–15 October. Our engineers will share practical work on high-velocity container builds and taming configuration explosion at scale. Come and meet us at our booth. #Bazel

Topiary v0.8.0 -- Irresistible Ironwood -- is out! 🌳 New: Tree-sitter language injections (Markdown code blocks, OCaml in OCamllex and Menhir), much richer error reporting, better multi-line strings and a --check flag for CI. github.com/topiary/topi...

Seven years later, Nix flakes are still experimental. At #NixCon2026, Tweag’s Valentin Gagarin will explain why he changed his mind about flakes and why he thinks the controversy was never really about the technology itself. 📅 27 September 🕘 09:00–09:45 📍Room A

Your coding agent read the instructions an hour ago. Does it still remember them? Victor Nascimento Bakke on tricorder-mcp, the new MCP server for Tricorder, our Haskell dev tool – and why it keeps agents on track in long sessions. tweag.io/blog/2026-09...

Sandboxed Nix builds are great. Rebuilding for the 42nd time? Less so. At #NixCon2026, Tweag’s Guillaume Maudoux will talk about Nixception: fast incremental builds without giving up sandboxing, using the same cache inside and outside the sandbox. 📅 26 September 🕝 14:30–15:15 📍Room A

A new release of rules_nixpkgs is here 🚀 v0.14.0 adds full support for Bazel 7, support for depending on Nix flakes and FlakeHub-backed packages, and support for export/propagation of package licenses. registry.bazel.build/modules/rule...

We’re heading to #NixCon2026. 👋 We’ll be in Kraków from 25–28 September, as a Silver Sponsor. Our engineers will be attending and speaking throughout the event. Working on adopting or scaling Nix? Come and talk to us. #nixcon #nixos

Liquid Haskell can prove your type class laws with an SMT solver – or could, until GHC 9 broke it. Juan Pablo Yamamoto spent #GSoC bringing it back. Here's how it went: tweag.io/blog/2026-09... #Haskell

@aspiwack.bsky.social specified a tiny SAT solver in Rocq and let a coding agent write the code and proofs. Once the agent stopped duplicating his entire program to dodge a proof, one question remains: Are we formal proofs yet? tweag.io/blog/2026-09...

Please follow us as we rewind five years to our very first Cardano smart contract audit. In this retrospective, Mathieu Montin shares the story and lessons behind those five years. www.tweag.io/blog/2026-07...

The Diff package adopts LiquidHaskell! The documentation of Diff was revamped and some of it is now checked automatically, with more static checks coming. Great work by Xavier Góngora. Check✅it out! discourse.haskell.org/t/diff-packa...

🌳 Topiary now supports Language Injections, formatting "forests" of syntax trees embedded in one another—OCaml inside OCamllex, Rust/JSON blocks inside Markdown—without breaking the host layout. Read all about how we leveraged Tree-sitter to make this happen: www.tweag.io/blog/2026-07...

I wrote about my sheaves project in prose form. Code, even small as that project, doesn't give you a lot of navigation keys. So I wanted to make something a bit more sequential to help get the important points across. Let me know if it helps.

In his latest blog post, @aspiwack.bsky.social shows how, despite textbook definitions suggesting the contrary, sheaves (from category theory) can be implemented in ordinary functional programming languages. www.tweag.io/blog/2026-06...

In his latest blog post, Xavier Góngora dove into a Haskell library and used Liquid Haskell to statically check invariants that were previously only implicit. His verdict on the tooling today? "No blood, sweat and tears; just ripples, but encouraging ones at that." www.tweag.io/blog/2026-06...

Announcing tricorder, an incremental build tool for Haskell: multi-component auto-discovery, a background build daemon and a TUI dashboard. Great to pair with LLM agents: it has a context-friendly CLI and includes a skill for tight feedback loops. tinyurl.com/dmpc8mbk

Introducing Scrawls 🦀 A #Rust library to read, write and verify SCLS files (CIP-0165): canonical #Cardano ledger-state snapshots with Blake2b-224 Merkle-tree integrity. Streaming, lazy and interoperable with the Haskell reference. 📦 crates.io/crates/carda...

cooked-validators v9.0.0 is out! • Revamped effect system (Polysemy) • Refined balancing mechanism • Extended temporal logic DSL github.com/tweag/cooked...

Check out the new blog!

build //newsletter issue 31 just dropped From remote caching tricks to running Claude prompts as Bazel actions, plus how to stop external resources breaking your builds .. there's something for every build nerd in this issue. BazelCon '26 in Amsterdam, who's going? build.news

Genealogos v1.1.0 is out! 👀 This release adds CycloneDX 1.5 support, updated dependencies, and fixes for `nix run`. Full details: github.com/tweag/geneal...

New release: linear-base v0.8.0 github.com/tweag/linear... . With some love shown to the resource-aware IO monad from contributor @dfacastro.bsky.social in support of their fascinating linear-locks library hackage.haskell.org/package/line...

FLOPS 2026, the 18th International Symposium on Functional Programming is less than 2 weeks away. The proceedings are available now in LNCS! link.springer.com/book/10.1007...

"linear-locks: locking primitives free of deadlocks" If you encounter STM's limitations when it comes to lock-free synchronisation, then Linear Haskell-backed locks maybe the solution you want! discourse.haskell.org/t/ann-linear... #Haskell

The Haskell Paris Spring Meetup will happen on the 27h of May at ENS Ulm. See the announcement here: discourse.haskell.org/t/haskell-pa... Register here: www.meetup.com/fr-FR/haskel...

You can take a look at their engineering blog: exploring-better-ways.bellroy.com/teams/techno...

The Lambda Nantes Meetup will happen on the 21st of May, with speakers @clementd.wtf and @etorreborre.blog as speakers discourse.haskell.org/t/lambda-nan...

The Tokyo Haskell Meetup will happen on the 19th of May with speakers Luite Stegeman and Farhad Mehta Discourse: discourse.haskell.org/t/haskell-me... Meetup: www.meetup.com/tokyo-haskel...

Attention all #Haskell fans: #MuniHac, our annual Haskell gathering, will take place in Munich from October 9th to 11th. Join us for a weekend of coding, learning, and hanging out with the international Haskell community. More information and the registration: munihac.de/2026.html

Congratulations Clash!

We sat down with Torsten Grust who is a professor of DB systems at the University of Tübingen. We talked about the best way to program databases, how to bridge the gap between regular programming languages and databases, and compiling just about everything to SQL. haskell.foundation/podcast/81/

A successful experiment in giving Haskell Rust-like affine discipline! Eventually, you might be able to run Haskell with completely predictable memory behavior in both scope and timing! This is absolutely wonderful: discourse.haskell.org/t/pure-borro...

Pure Borrow: Linear Haskell Meets Rust-Style Borrowing discourse.haskell.org/t/pure-borro...

A quick thread-of-thread of my observation on my small sheaves-in-Haskell project from the other week.

After a somewhat longer break, we're finally back with a new #Haskell #Unfolder episode. Tomorrow, 2026-04-22, at 18:30 UTC, Edsko and I will talk about selective applicative functors. www.youtube.com/watch?v=Yt2E...

Curious what's new in Rust 1.95.0? Check out this video of Cameron, Pete, and Tyler discussing the new release: www.youtube.com/watch?v=NZlm...

When your README's a monolith, doc it like it's hot! xophmeister.hachyderm.io.ap.brid.gy walks through three projects where documentation earned its place, featuring a crew of unlikely collaborators 🎤 www.tweag.io/blog/2026-04...

In this episode from POPL 2026, we talk about: undergrad funding and participation, the behind the scenes of AV, choreographic programming, quantum languages, conference catering, and the joy of theory. haskell.foundation/podcast/80

Software Heritage is building the world's largest source code archive🌍💻 We’re #hiring for key roles in France: • Backend Engineer • DevOps Engineer • Internal Apps Manager Join our mission! ➡️ https://www.softwareheritage.org/jobs