nix3-print-dev-env

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

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.