Warning: This program is experimental and its interface is subject to change.
Name
nix flake metadata
- show flake metadata
Synopsis
nix flake metadata
[option...] flake-url
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 thedescription
field inflake.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 forgithub
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
andoriginalUrl
: The flake reference specified by the user (flake-url) in attribute set and URL representation. -
resolved
andresolvedUrl
: The resolved flake reference (see above) in attribute set and URL representation. -
locked
andlockedUrl
: The locked flake reference (see above) in attribute set and URL representation. -
description
: SeeDescription
above. -
path
: SeePath
above. -
revision
: SeeRevision
above. -
revCount
: SeeRevisions
above. -
lastModified
: SeeLast modified
above. -
locks
: The contents offlake.lock
.
Options
--json
Produce output in JSON format, suitable for consumption by another program.
Common evaluation options:
-
--arg
name expr
Pass the value expr as the argument name to Nix functions. -
--argstr
name string
Pass the string string as the argument name to Nix functions. -
--eval-store
store-url
The Nix store to use for evaluations. -
--impure
Allow access to mutable paths and repositories. -
--include
/-I
path
Add path to the list of locations used to look up<...>
file names. -
--override-flake
original-ref resolved-ref
Override the flake registries, redirecting original-ref to resolved-ref.
Common flake-related options:
-
--commit-lock-file
Commit changes to the flake's lock file. -
--inputs-from
flake-url
Use the inputs of the specified flake as registry entries. -
--no-registries
Don't allow lookups in the flake registries. This option is deprecated; use--no-use-registries
. -
--no-update-lock-file
Do not allow any updates to the flake's lock file. -
--no-write-lock-file
Do not write the flake's newly generated lock file. -
--override-input
input-path flake-url
Override a specific flake input (e.g.dwarffs/nixpkgs
). This implies--no-write-lock-file
. -
--recreate-lock-file
Recreate the flake's lock file from scratch. -
--update-input
input-path
Update a specific flake input (ignoring its previous entry in the lock file).