Nix/src/nix/flake-metadata.md

3.6 KiB

R""(

Examples

  • Show what nixpkgs resolves to:

    # nix flake metadata nixpkgs
    Resolved URL:  github:edolstra/dwarffs
    Locked URL:    github:edolstra/dwarffs/f691e2c991e75edb22836f1dbe632c40324215c5
    Description:   A filesystem that fetches DWARF debug info from the Internet on demand
    Path:          /nix/store/769s05vjydmc2lcf6b02az28wsa9ixh1-source
    Revision:      f691e2c991e75edb22836f1dbe632c40324215c5
    Last modified: 2021-01-21 15:41:26
    Inputs:
    ├───nix: github:NixOS/nix/6254b1f5d298ff73127d7b0f0da48f142bdc753c
    │   ├───lowdown-src: github:kristapsdz/lowdown/1705b4a26fbf065d9574dce47a94e8c7c79e052f
    │   └───nixpkgs: github:NixOS/nixpkgs/ad0d20345219790533ebe06571f82ed6b034db31
    └───nixpkgs follows input 'nix/nixpkgs'
    
  • Show information about dwarffs in JSON format:

    # nix flake metadata dwarffs --json | jq .
    {
      "description": "A filesystem that fetches DWARF debug info from the Internet on demand",
      "lastModified": 1597153508,
      "locked": {
        "lastModified": 1597153508,
        "narHash": "sha256-VHg3MYVgQ12LeRSU2PSoDeKlSPD8PYYEFxxwkVVDRd0=",
        "owner": "edolstra",
        "repo": "dwarffs",
        "rev": "d181d714fd36eb06f4992a1997cd5601e26db8f5",
        "type": "github"
      },
      "locks": { ... },
      "original": {
        "id": "dwarffs",
        "type": "indirect"
      },
      "originalUrl": "flake:dwarffs",
      "path": "/nix/store/hang3792qwdmm2n0d9nsrs5n6bsws6kv-source",
      "resolved": {
        "owner": "edolstra",
        "repo": "dwarffs",
        "type": "github"
      },
      "resolvedUrl": "github:edolstra/dwarffs",
      "revision": "d181d714fd36eb06f4992a1997cd5601e26db8f5",
      "url": "github:edolstra/dwarffs/d181d714fd36eb06f4992a1997cd5601e26db8f5"
    }
    

Description

This command shows information about the flake specified by the flake reference flake-url. It resolves the flake reference using the flake registry, fetches it, and prints some meta data. This includes:

  • Resolved URL: If flake-url is a flake identifier, then this is the flake reference that specifies its actual location, looked up in the flake registry.

  • Locked URL: A flake reference that contains a commit or content hash and thus uniquely identifies a specific flake version.

  • Description: A one-line description of the flake, taken from the description field in flake.nix.

  • Path: The store path containing the source code of the flake.

  • Revision: The Git or Mercurial commit hash of the locked flake.

  • Revisions: The number of ancestors of the Git or Mercurial commit of the locked flake. Note that this is not available for github flakes.

  • Last modified: For Git or Mercurial flakes, this is the commit time of the commit of the locked flake; for tarball flakes, it's the most recent timestamp of any file inside the tarball.

  • Inputs: The flake inputs with their corresponding lock file entries.

With --json, the output is a JSON object with the following fields:

  • original and originalUrl: The flake reference specified by the user (flake-url) in attribute set and URL representation.

  • resolved and resolvedUrl: The resolved flake reference (see above) in attribute set and URL representation.

  • locked and lockedUrl: The locked flake reference (see above) in attribute set and URL representation.

  • description: See Description above.

  • path: See Path above.

  • revision: See Revision above.

  • revCount: See Revisions above.

  • lastModified: See Last modified above.

  • locks: The contents of flake.lock.

)""