2023-12-08 Nix team meeting minutes #110


Attendees: @Ericson2314 @thufschmitt @edolstra @tomberek @roberth


  • Triage
  • Hydra status


  • Backport of a pure refactoring
    • @edolstra: Kinda scary because it’s a big change
    • @thufschmitt: We could backport it when/if needed, but shouldn’t do that eagerly
    • Agreement on closing the PR until we need it

Allow getting in a MinGW dev shell by Ericson2314 · Pull Request #9519 · NixOS/nix · GitHub


Warn when End Of Life · Issue #9556 · NixOS/nix · GitHub

Warn people when they use an old version.

  • @edolstra: Can be very annoying for people although their Nix works fine otherwise
  • @roberth: If you’re stuck with an old Nix, you’re asking for trouble, and you should opt into that explicitely
  • Needs further discussion


  • 2.19’s changes caused …? [@roberth add that bit?]

  • Some question about predicate functions vs locales

`json-meta://` store by Ericson2314 · Pull Request #9551 · NixOS/nix · GitHub

  • New store type that stores the metadata in json files rather than an SQLite database
  • Use cases
    • layered/key-value filesystems (OCI, ZFS, S3)
    • Easy to diff and test changes
    • Agreement on merging the refactoring parts and keep the store implementation itself out of tree


Deferring triage until issues mentioned async are fixed.

Nix team · GitHub

Goal: Do more development-related work in addition to maintenance

Related: Start a Flakes milestone list · Issue #8870 · NixOS/nix · GitHub

@roberth: We need to do something to keep track of what’s in the way of our projects, in particular flakes stabilisation

The team will block 1h next monday to triage the flakes and new-cli issues and see which ones are blocking the stabilisation

Get rid of the `--derivation` flag by Ericson2314 · Pull Request #8594 · NixOS/nix · GitHub

  • @ericson2314 less special syntax in the CLI would be better
  • proposal - someDerivation^.. is the drvPath as a store level operation
  • CLI behavior needs to be defined
  • NixStringContextElem::DrvDeep behavior?
    • Ericson2314: just stop worry about that!
  • in a package where .doc is built by a different derivation than .out, we’ll want ^.. so we can do pkg.doc^.. to get the --derivation behavior for that output, but this is not supported in the CLI yet anyway.

(post meeting more discussion)

  • Can we defer some of this stuff for later? (e.g. ^..)

    • yes
  • include examples in release notes

    • nix copy --derivation
    • nix why-depends --derivation
    • nix path-info --derivation
    • "${lib.getExe nix} ${lib.optionalString (lib.versionAtLeast nix.version "2.21???something") "--derivation "}"