Manpages - nix3-print-dev-env.1

Warning
This program is experimental and its interface is subject to change.

#+end_quote

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 operate on.
--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.
--arg-from-file name path Pass the contents of file path as the argument name to Nix functions.
--arg-from-stdin name Pass the contents of stdin as the argument name to Nix functions.
--argstr name string Pass the string string as the argument name to Nix functions.
--debugger Start an interactive environment if evaluation fails.
--eval-store store-url The URL of the Nix store to use for evaluation, i.e. to store derivations (.drv files) and inputs referenced by them.
--impure Allow access to mutable paths and repositories.
--include / -I path Add path to search path entries used to resolve lookup paths This option may be given multiple times. Paths added through -I take precedence over the nix-path configuration setting and the NIX_PATH environment variable.
--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.

DEPRECATED

Use --no-use-registries instead.
--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.
--output-lock-file flake-lock-path Write the given lock file instead of flake.lock within the top-level flake.
--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.

DEPRECATED

Use nix flake update instead.
--reference-lock-file flake-lock-path Read the given lock file instead of flake.lock within the top-level flake.
--update-input input-path

Update a specific flake input (ignoring its previous entry in the lock file).

DEPRECATED

Use nix flake update instead.

Logging-related options

--debug Set the logging verbosity level to ‘debug'.
--log-format format Set the format of log output; one of raw, internal-json, bar or bar-with-logs.
--print-build-logs / -L Print full build logs on standard error.
--quiet Decrease the logging verbosity level.
--verbose / -v Increase the logging verbosity level.

Miscellaneous global options

--help Show usage information.
--offline Disable substituters and consider all previously downloaded files up-to-date.
--option name value Set the Nix configuration setting name to value (overriding nix.conf).
--refresh Consider all previously downloaded files out-of-date.
--repair During evaluation, rewrite missing or corrupted files in the Nix store. During building, rebuild missing or corrupted store paths.
--version Show version information.

Options that change the interpretation of installables

--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. Implies --impure. Note See man nix.conf for overriding configuration settings with command line flags.