Name¶

nix print-dev-env - print shell code that can be sourced by bash to reproduce the build environment of a derivation

Synopsis¶

nix print-dev-env [option…] installable

Examples¶

•

Apply the build environment of GNU hello to the current shell:

# . <(nix print-dev-env nixpkgs#hello)

•

Get the build environment in JSON format:

# nix print-dev-env nixpkgs#hello --json

The output will look like this:

{
"bashFunctions": {


  "buildPhase": " \n    runHook preBuild;\n...",


  ...
},
"variables": {


  "src": {


    "type": "exported",


    "value": "/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz"


  },


  "postUnpackHooks": {


    "type": "array",


    "value": ["_updateSourceDateEpochFromSourceRoot"]


  },


  ...
}
}

Description¶

This command prints a shell script that can be sourced by bash and that sets the variables and shell functions defined by the build process of installable. This allows you to get a similar build environment in your current shell rather than in a subshell (as with nix develop).

With --json, the output is a JSON serialisation of the variables and functions defined by the build process.

Options¶

• --json
  Produce output in JSON format, suitable for consumption by another program.
• --profile path
  The profile to update.
• --redirect installable outputs-dir
  Redirect a store path to a mutable location.

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).

Options that change the interpretation of installables:

• --derivation
  Operate on the store derivation rather than its outputs.
• --expr expr
  Interpret installables as attribute paths relative to the Nix expression expr.
• --file / -f file
  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.