Name¶

nix derivation show - show the contents of a store derivation

Synopsis¶

nix derivation show [option…] installables…

Examples¶

•

Show the store derivation that results from evaluating the Hello package:

# nix derivation show nixpkgs#hello
{
"/nix/store/s6rn4jz1sin56rf4qj5b5v8jxjm32hlk-hello-2.10.drv": {


  …
}
}

•

Show the full derivation graph (if available) that produced your NixOS system:

# nix derivation show -r /run/current-system

•

Print all files fetched using fetchurl by Firefox’s dependency graph:

# nix derivation show -r nixpkgs#firefox \
| jq -r '.[] | select(.outputs.out.hash and .env.urls) | .env.urls' \
| uniq | sort

Note that .outputs.out.hash selects fixed-output derivations (derivations that produce output with a specified content hash), while .env.urls selects derivations with a urls attribute.

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.

nix derivation show outputs a JSON map of store paths to derivations in the following format:

Derivation JSON Format¶

The JSON serialization of a derivations is a JSON object with the following fields:

• name: The name of the derivation. This is used when calculating the store paths of the derivation’s outputs.
• 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:

Otherwise, null.

"outputs": {


  "out": {


    "path": "/nix/store/2543j7c6jn75blc3drf4g5vhb1rhdq29-source",


    "method": "nar",


    "hashAlgo": "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.

"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 dev output of curl, and the out output of unzip.

• 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 the bash shell (e.g. /nix/store/r3j288vpmczbl500w6zz89gyfa4nr0b1-bash-4.4-p23/bin/bash).
• args: The command-line arguments passed to the builder.
• env: The environment passed to the builder.
• structuredAttrs: Strucutured Attributes, only defined if the derivation contains them. Structured attributes are JSON, and thus embedded as-is.

Options¶

•

--no-pretty

Print compact JSON output on a single line, even when the output is a terminal. Some commands may print multiple JSON objects on separate lines.

            See `--pretty`.

•

--pretty

Print multi-line, indented JSON output for readability.

            Default: indent if output is to a terminal.


            This option is only effective when `--json` is also specified.

•

--recursive / -r

Include the dependencies of the specified derivations.

•

--stdin

Read installables from the standard input. No default installable applied.