Warning: This program is experimental and its interface is subject to change.
Name
nix show-derivation - show the contents of a store derivation
Synopsis
nix show-derivation [option...] installables...
Examples
-
Show the store derivation that results from evaluating the Hello package:
# nix show-derivation nixpkgs#hello { "/nix/store/s6rn4jz1sin56rf4qj5b5v8jxjm32hlk-hello-2.10.drv": { … } } -
Show the full derivation graph (if available) that produced your NixOS system:
# nix show-derivation -r /run/current-system -
Print all files fetched using
fetchurlby Firefox's dependency graph:# nix show-derivation -r nixpkgs#firefox \ | jq -r '.[] | select(.outputs.out.hash and .env.urls) | .env.urls' \ | uniq | sortNote that
.outputs.out.hashselects fixed-output derivations (derivations that produce output with a specified content hash), while.env.urlsselects derivations with aurlsattribute.
Description
This command prints on standard output a JSON representation of the
store derivations to which installables evaluate. Store derivations
are used internally by Nix. They are store paths with extension .drv
that represent the build-time dependency graph to which a Nix
expression evaluates.
By default, this command only shows top-level derivations, but with
--recursive, it also shows their dependencies.
The JSON output is a JSON object whose keys are the store paths of the derivations, and whose values are a JSON object with the following fields:
-
outputs: Information about the output paths of the derivation. This is a JSON object with one member per output, where the key is the output name and the value is a JSON object with these fields:path: The output path.hashAlgo: For fixed-output derivations, the hashing algorithm (e.g.sha256), optionally prefixed byr:ifhashdenotes a NAR hash rather than a flat file hash.hash: For fixed-output derivations, the expected content hash in base-16.
Example:
"outputs": { "out": { "path": "/nix/store/2543j7c6jn75blc3drf4g5vhb1rhdq29-source", "hashAlgo": "r:sha256", "hash": "6fc80dcc62179dbc12fc0b5881275898f93444833d21b89dfe5f7fbcbb1d0d62" } } -
inputSrcs: A list of store paths on which this derivation depends. -
inputDrvs: A JSON object specifying the derivations on which this derivation depends, and what outputs of those derivations. For example,"inputDrvs": { "/nix/store/6lkh5yi7nlb7l6dr8fljlli5zfd9hq58-curl-7.73.0.drv": ["dev"], "/nix/store/fn3kgnfzl5dzym26j8g907gq3kbm8bfh-unzip-6.0.drv": ["out"] }specifies that this derivation depends on the
devoutput ofcurl, and theoutoutput ofunzip. -
system: The system type on which this derivation is to be built (e.g.x86_64-linux). -
builder: The absolute path of the program to be executed to run the build. Typically this is thebashshell (e.g./nix/store/r3j288vpmczbl500w6zz89gyfa4nr0b1-bash-4.4-p23/bin/bash). -
args: The command-line arguments passed to thebuilder. -
env: The environment passed to thebuilder.
Options
--recursive/-r
Include the dependencies of the specified derivations.
Common evaluation options:
-
--argname expr
Pass the value expr as the argument name to Nix functions. -
--argstrname string
Pass the string string as the argument name to Nix functions. -
--eval-storestore-url
The Nix store to use for evaluations. -
--impure
Allow access to mutable paths and repositories. -
--include/-Ipath
Add path to the list of locations used to look up<...>file names. -
--override-flakeoriginal-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-fromflake-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-inputinput-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-inputinput-path
Update a specific flake input (ignoring its previous entry in the lock file).
Options that change the interpretation of installables:
-
--derivation
Operate on the store derivation rather than its outputs. -
--exprexpr
Interpret installables as attribute paths relative to the Nix expression expr. -
--file/-ffile
Interpret installables as attribute paths relative to the Nix expression stored in file. If file is the character -, then a Nix expression will be read from standard input.