{"$schema": "https://c3voc.de/schedule/schema.json", "generator": {"name": "pretalx", "version": "2025.2.2"}, "schedule": {"url": "https://pretalx.dgnum.eu/lixcon-2026/schedule/", "version": "0.5", "base_url": "https://pretalx.dgnum.eu", "conference": {"acronym": "lixcon-2026", "title": "LixCon 2026", "start": "2026-04-17", "end": "2026-04-19", "daysCount": 3, "timeslot_duration": "00:05", "time_zone_name": "Europe/Paris", "colors": {"primary": "#d162a4"}, "rooms": [{"name": "Amphitheater Dussane", "slug": "1-amphitheater-dussane", "guid": "4c6a19ab-b527-5b15-bfef-31e821ea155f", "description": null, "capacity": 200}, {"name": "Salle des R\u00e9sistants", "slug": "2-salle-des-resistants", "guid": "879e7046-e9cc-5bd3-ab87-418c33fa01dd", "description": null, "capacity": 50}, {"name": "Salle des Actes", "slug": "3-salle-des-actes", "guid": "2d43db66-a32a-5236-9059-35a0a99e3215", "description": null, "capacity": 80}, {"name": "Salle Beckett", "slug": "4-salle-beckett", "guid": "926197fe-5188-535a-a91d-b68fca779d21", "description": null, "capacity": null}, {"name": "Salle Cavaill\u00e8s", "slug": "5-salle-cavailles", "guid": "0ada3adb-5417-5736-9444-758c75dfcb0c", "description": null, "capacity": null}, {"name": "Salle Celan", "slug": "6-salle-celan", "guid": "c85f92f4-f48c-5220-8477-2cf343b88007", "description": "Hacking room for saturday and sunday", "capacity": 30}], "tracks": [], "days": [{"index": 1, "date": "2026-04-17", "day_start": "2026-04-17T04:00:00+02:00", "day_end": "2026-04-18T03:59:00+02:00", "rooms": {"Amphitheater Dussane": [{"guid": "378ba267-be86-570c-90c9-3c58132d3721", "code": "38JNUB", "id": 9, "logo": null, "date": "2026-04-17T10:00:00+02:00", "start": "10:00", "duration": "00:15", "room": "Amphitheater Dussane", "slug": "lixcon-2026-9-introduction-to-lixcon", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/38JNUB/", "title": "Introduction to LixCon", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "Welcome to LixCon!", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "WKHL9Y", "name": "Ryan Lahfa (\"RaitoBezarius\")", "avatar": null, "biography": null, "public_name": "Ryan Lahfa (\"RaitoBezarius\")", "guid": "4df0a2a7-73d9-5c96-9e6c-12ffe64aed65", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/WKHL9Y/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/38JNUB/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/38JNUB/", "attachments": []}, {"guid": "238ae78e-b9c5-5e6a-98e7-8412f3137205", "code": "YZZKYT", "id": 8, "logo": null, "date": "2026-04-17T10:15:00+02:00", "start": "10:15", "duration": "00:15", "room": "Amphitheater Dussane", "slug": "lixcon-2026-8-botanix-a-nix-native-ci-in-a-forge-agnostic-world", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/YZZKYT/", "title": "Botanix: A Nix native CI in a forge-agnostic world", "subtitle": "", "track": null, "type": "Short talk", "language": "en", "abstract": "Botanix is a new CI software that targets a native nix integration as it builds derivations as its pipeline. It integrates natively with both Gerrit and Forgejo currently but its genericity allows for even more diversity in the future!\r\n\r\nThis talk will present the genesis of the Botanix project, worked on by students from ENS de Lyon, its philosophy and inner workings.", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "39PK93", "name": "Tom Hubrecht", "avatar": null, "biography": "A phd student in floating-point arithmetic at ENS de Lyon and treasurer for AFNix.", "public_name": "Tom Hubrecht", "guid": "07c0ed95-ad99-51aa-9d9d-d09b2b98d941", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/39PK93/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/YZZKYT/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/YZZKYT/", "attachments": []}, {"guid": "4f093efc-1c60-5d96-a861-e3f77747b156", "code": "PEDV9S", "id": 13, "logo": null, "date": "2026-04-17T10:45:00+02:00", "start": "10:45", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-13-the-untapped-potential-of-lix-plugins", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/PEDV9S/", "title": "The untapped potential of Lix plugins", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "Lix plugins \u2014 a feature so esoteric none yet remember their existence. What power could they hold? What secrets could they unlock? Let's discover together!", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "MNLV8K", "name": "Qyriad", "avatar": "https://pretalx.dgnum.eu/media/avatars/MNLV8K_YMTFUCw.webp", "biography": "I'm Qyriad, a build systems engineer and systems programmer. My programs are better than my puns.", "public_name": "Qyriad", "guid": "2f110203-e3d4-544b-92c4-1d44797e45bd", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/MNLV8K/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/PEDV9S/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/PEDV9S/", "attachments": []}, {"guid": "d92f0715-b3ef-513e-b188-0f392ec59017", "code": "HVZTB9", "id": 3, "logo": null, "date": "2026-04-17T11:15:00+02:00", "start": "11:15", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-3-the-politics-of-language-design", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/HVZTB9/", "title": "The politics of language design", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "This talk is about Elpe, a mixture of ideas from Nix, Docker and Ubuntu/Debian/RHEL, with a strong focus on performance and security.\r\n\r\nI'll talk about the design choices I've made, and demo the thing and about how choices that may seem purely technical can have extreme political consequences. I'll also explain how such choices can have deep and lasting consequences on the dynamics of growing organisations.", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "NPVMBK", "name": "Pierre-\u00c9tienne Meunier", "avatar": null, "biography": "I like things that compute, even more so if they aren't computers. After 15 years in academia programming molecules, I'm now programming homo economicuses sharing electricity.\r\n\r\nI like programming computers too, especially distributed things like version control.", "public_name": "Pierre-\u00c9tienne Meunier", "guid": "de14327e-4d62-5e01-9666-0e34cdbde9ee", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/NPVMBK/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/HVZTB9/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/HVZTB9/", "attachments": []}, {"guid": "96146e73-9f8c-5b23-9a33-e22dedae57ea", "code": "F83VYV", "id": 4, "logo": null, "date": "2026-04-17T11:45:00+02:00", "start": "11:45", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-4-regiux-prototyping-a-fast-nix-interpreter", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/F83VYV/", "title": "Regiux: prototyping a fast Nix interpreter", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "The Nix expression language is challenging to evaluate due to non-strict semantics, dynamic scoping, a diverse collection of builtin operators, and tight integration with the Nix store. We give a progress report on Regiux, an interpreter for Nix which is narrowly focused on efficient evaluation of expressions.", "description": "Regiux is yet another attempt at a fast Nix evaluator. Come learn about the ingredients that go into modern compilers and interpreters, particularly:\r\n\r\n* Lexing and parsing\r\n* Desugaring and expanding\r\n* Intermediate languages for lambda calculus\r\n* Using the RPython JIT toolkit\r\n* Bytecode for lazy graph evaluation", "recording_license": "", "do_not_record": false, "persons": [{"code": "QXGN79", "name": "Corbin", "avatar": null, "biography": "Corbin Simpson is a logician from Oregon. His interests include jazz piano, speedrunning, compiler engineering, site reliability engineering, and information security. Corbin has been a NixOS contributor for about a decade.", "public_name": "Corbin", "guid": "a38948f7-01eb-5a72-b98f-d9577a803d8b", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/QXGN79/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/F83VYV/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/F83VYV/", "attachments": [{"title": "Slides v1", "url": "/media/lixcon-2026/submissions/F83VYV/resources/regiux_EMrN9lj.pdf", "type": "related"}, {"title": "Slides v2", "url": "/media/lixcon-2026/submissions/F83VYV/resources/regiux_rFoETDd.pdf", "type": "related"}]}, {"guid": "6c07eb5b-50b1-5587-9c1a-d1f679192bf4", "code": "A7BNGC", "id": 12, "logo": null, "date": "2026-04-17T13:45:00+02:00", "start": "13:45", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-12-meltwater-rapids", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/A7BNGC/", "title": "meltwater rapids", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "the ice caps are melting, ~~meteors are getting crashed into us~~ global warming stops for nothing and no one. the meltwater has to go somewhere. hope you brought a good boat.", "description": "a brief look into the more recent history of lix dealing with tech debt, and where we want to go from here", "recording_license": "", "do_not_record": true, "persons": [{"code": "XYZGV3", "name": "eldritch horrors", "avatar": null, "biography": "are you going to eat that?", "public_name": "eldritch horrors", "guid": "c9db6c78-49d1-50f0-b38a-0e2a370258fa", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/XYZGV3/"}, {"code": "B3D9SZ", "name": "Raito", "avatar": null, "biography": null, "public_name": "Raito", "guid": "737040db-bc5a-50d4-9679-5f703d269ca4", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/B3D9SZ/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/A7BNGC/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/A7BNGC/", "attachments": []}, {"guid": "dafe38a9-1feb-5273-90f2-5fc8ef102b62", "code": "KBFUXL", "id": 1, "logo": null, "date": "2026-04-17T14:15:00+02:00", "start": "14:15", "duration": "00:15", "room": "Amphitheater Dussane", "slug": "lixcon-2026-1-to-sleep-in-a-sea-of-tests-refactoring-a-testing-framework-from-hell", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/KBFUXL/", "title": "To sleep in a sea of Tests | Refactoring a testing \"framework\" from hell", "subtitle": "", "track": null, "type": "Short talk", "language": "en", "abstract": "Taking a look at the `functional` test suite, pointing out its concepts and flaws to then take a look at its successor `functional2`", "description": "Many curses and screams of frustration has the functional test suite brought forth in many - if not all - lix developers. Hence people wanted a successor. \r\nIn this session, we will talk about all the pain, impurities and falkeyness of the functional suite, look at the features and non-features of functional2, and the pain of migrating tests.", "recording_license": "", "do_not_record": false, "persons": [{"code": "QGSWNB", "name": "rootile", "avatar": "https://pretalx.dgnum.eu/media/avatars/QGSWNB_S1PgIXF.webp", "biography": "Code owner of the functional2 test suite", "public_name": "rootile", "guid": "8d42be1d-f79d-5390-8f08-75825145a1e9", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/QGSWNB/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/KBFUXL/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/KBFUXL/", "attachments": [{"title": "Slides", "url": "/media/lixcon-2026/submissions/KBFUXL/resources/lixcon2026_talk_nLXtRSQ.pdf", "type": "related"}]}, {"guid": "9e126251-90f9-5624-86f7-e41befee6d6b", "code": "Z3CRCM", "id": 2, "logo": null, "date": "2026-04-17T14:50:00+02:00", "start": "14:50", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-2-nix-and-buck2-from-enemies-to-lovers-with-snowydeer", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/Z3CRCM/", "title": "Nix and buck2: from enemies to lovers with snowydeer", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "Nix does dependencies and distribution well, but has a controlling personality: it wants to build everything in the build graph.\r\nBuck2 delivers fast, user-friendly, and scalable project builds, but has an equally controlling personality and a lacking public dependency ecosystem.\r\nWhat if their build graphs touched ... and they were both girls?\r\n\r\nIn this talk, I will demonstrate how we go from Nix to buck2 to Nix then deploy with containers:\r\n* Using Nix for dependencies in buck2\r\n* Using buck2 in the project build: remote caching, fast builds, ~zero evaluation time\r\n* Importing store paths to Lix from buck2 output while correctly handling dependencies\r\n* Extending these techniques to build Docker images defined entirely in buck2, using nixpkgs `dockerTools`\r\n\r\nThis talk focuses on buck2, but the techniques used apply to any powerful non-Nix build system.\r\n\r\nSlides: <https://jade.fyi/lixcon2026>", "description": "Hermetic build systems are hard to interoperate with, but there are cheat codes: by resolving their trust issues, you can combine their respective benefits.\r\n\r\nFor the last year, my team and I have been working on a Buck2 migration for one of the largest Haskell codebases in industry to reduce build times from dozens of minutes to seconds and improve user experience.\r\nWe use Nix to orchestrate hundreds of Haskell dependencies and hundreds more dependencies across the Rust, TypeScript, Python and C ecosystems.\r\nOn top of that, we are running a much newer Haskell compiler than most of the industry due to active involvement in GHC development, which means a *heavily* patched nixpkgs Haskell dependency set to be able to incorporate these improvements.\r\nBy building a Nix-Buck2-Nix sandwich, we were able to focus on rewriting our product build in buck2 while keeping both our Nix-based dependencies and our deployment pipelines to both NixOS and AWS ECS completely as-is.\r\n\r\nThe novel contributions of this talk are:\r\n* Creating full-featured store paths *entirely* outside of Nix with Snowydeer:\r\n  * Reference scanning outside of Nix using ripgrep\r\n  * Using a new Lix CLI feature: output-addressed paths with references\r\n  * Referencing those store paths from Nix language for further processing\r\n* Using Nix as a build step rather than a build driver to create an ergonomic Docker image builder with Snowydeer Container\r\n\r\nThis talk builds on previous work, such as:\r\n- [\"Integrating Nix and Buck2 for fun and profit\"](https://www.youtube.com/watch?v=pDkFk7iggIE) by Claudio Bley\r\n- [\"Haskell Builds at Scale: Comparing Bazel and Buck2\"](https://www.youtube.com/watch?v=eA-3Gfr4epU) by Andreas Herrmann\r\n- [\"Towards Dream Haskell Build Experience\"](https://www.youtube.com/watch?v=WrdXUYFnRv4) by Ian-Woo Kim", "recording_license": "", "do_not_record": false, "persons": [{"code": "HXNSGL", "name": "Jade Lovelace", "avatar": null, "biography": "Jade is a build system engineer and yuri enthusiast. They are passionate about building transformational tooling for a better future of computing for everyone, allowing individuals and small organizations to effectively and understandably control their own computing. Outside of their work, they enjoy photography and dark room printing.", "public_name": "Jade Lovelace", "guid": "27fb6061-51b2-5319-a625-1f8a7a789dab", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/HXNSGL/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/Z3CRCM/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/Z3CRCM/", "attachments": []}, {"guid": "5f27f28d-189d-5fcb-af63-f999f2992a61", "code": "QFSZRU", "id": 14, "logo": null, "date": "2026-04-17T15:20:00+02:00", "start": "15:20", "duration": "00:30", "room": "Amphitheater Dussane", "slug": "lixcon-2026-14-using-nix-without-the-nix-a-retrospective-on-zilch", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/QFSZRU/", "title": "Using Nix without the Nix: a Retrospective on Zilch", "subtitle": "", "track": null, "type": "Talk", "language": "en", "abstract": "It's been a while since I last talked about Zilch; and now with Lix's existence, it's time to take another look; what's the status of this mysterious project, and what lessons can we learn from it?", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "DZVGEM", "name": "Puck", "avatar": "https://pretalx.dgnum.eu/media/avatars/DZVGEM_pwb8Cus.webp", "biography": "Hi. I'm Puck. I do weird things, and sometimes those things are Nix-related.", "public_name": "Puck", "guid": "f1fa40b3-dc07-55a2-91a2-15b084553ca7", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/DZVGEM/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/QFSZRU/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/QFSZRU/", "attachments": []}, {"guid": "90f7b54c-6500-5ae5-b8a4-0f1ba853601e", "code": "EYHR9T", "id": 15, "logo": null, "date": "2026-04-17T15:50:00+02:00", "start": "15:50", "duration": "00:15", "room": "Amphitheater Dussane", "slug": "lixcon-2026-15-lixcon-outro", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EYHR9T/", "title": "LixCon outro", "subtitle": "", "track": null, "type": "Short talk", "language": "en", "abstract": "Outro of LixCon, onwards on the hacking session", "description": "", "recording_license": "", "do_not_record": false, "persons": [{"code": "WKHL9Y", "name": "Ryan Lahfa (\"RaitoBezarius\")", "avatar": null, "biography": null, "public_name": "Ryan Lahfa (\"RaitoBezarius\")", "guid": "4df0a2a7-73d9-5c96-9e6c-12ffe64aed65", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/WKHL9Y/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EYHR9T/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EYHR9T/", "attachments": []}], "Salle des Actes": [{"guid": "13541748-1c03-5c68-99a6-85fce4363b3e", "code": "EW3JLJ", "id": 11, "logo": null, "date": "2026-04-17T14:30:00+02:00", "start": "14:30", "duration": "00:30", "room": "Salle des Actes", "slug": "lixcon-2026-11-updates-from-lix-nix-lang-land", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EW3JLJ/", "title": "Updates from Lix' Nix-lang land", "subtitle": "", "track": null, "type": "Discussion format", "language": "en", "abstract": "Let's talk about the current state of the Nix language and evaluator, and where things are headed. Nix lang2 (https://wiki.lix.systems/books/development/page/nix-lang-v2), language versioning (https://github.com/NixOS/rfcs/pull/137), bytecode, Rust and more.\r\n\r\nThis will be more like a semi-structured infodump with some Q&A than a proper talk. Slides are unlikely to be prepared for this. No public recordings, but the plan is to take the transcript and compile it down into a blog post or something.", "description": "", "recording_license": "", "do_not_record": true, "persons": [{"code": "K78HNH", "name": "piegames", "avatar": "https://pretalx.dgnum.eu/media/avatars/K78HNH_fXh09Bu.webp", "biography": "I work on compilers for fun and decompilers for profit", "public_name": "piegames", "guid": "9b1f6377-4b9e-5fb3-8b56-d68a69bf2531", "url": "https://pretalx.dgnum.eu/lixcon-2026/speaker/K78HNH/"}], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EW3JLJ/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/EW3JLJ/", "attachments": []}]}}, {"index": 2, "date": "2026-04-18", "day_start": "2026-04-18T04:00:00+02:00", "day_end": "2026-04-19T03:59:00+02:00", "rooms": {"Amphitheater Dussane": [{"guid": "26896b81-51b6-5d37-a7a3-8e6d201ad4a0", "code": "7CR3VM", "id": 22, "logo": null, "date": "2026-04-18T14:00:00+02:00", "start": "14:00", "duration": "01:00", "room": "Amphitheater Dussane", "slug": "lixcon-2026-22-afnix-ga", "url": "https://pretalx.dgnum.eu/lixcon-2026/talk/7CR3VM/", "title": "Afnix GA", "subtitle": "", "track": null, "type": "Afnix GA", "language": "en", "abstract": "General Assembly of the Association Fran\u00e7aise Nix", "description": "General Assembly of the Association Fran\u00e7aise Nix (AFNix - https://afnix.fr), non-profit organization providing legal and technical infrastructure for Nix community projects. We help make Lix possible! This General Assembly meeting is open to the public to listen in, however please be advised that active participation will be limited to organization members only. AFNix members will be available throughout the entire LixCon event for open discussion.", "recording_license": "", "do_not_record": false, "persons": [], "links": [], "feedback_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/7CR3VM/feedback/", "origin_url": "https://pretalx.dgnum.eu/lixcon-2026/talk/7CR3VM/", "attachments": []}]}}, {"index": 3, "date": "2026-04-19", "day_start": "2026-04-19T04:00:00+02:00", "day_end": "2026-04-20T03:59:00+02:00", "rooms": {}}]}}}