plucky (1) nix3-print-dev-env.1.gz
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 ⟨./nix.md#installables⟩. 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 ⟨#opt-json⟩
Produce output in JSON format, suitable for consumption by another program.
• --profile ⟨#opt-profile⟩ path
The profile to operate on.
• --redirect ⟨#opt-redirect⟩ installable outputs-dir
Redirect a store path to a mutable location.
Common evaluation options
• --arg ⟨#opt-arg⟩ name expr
Pass the value expr as the argument name to Nix functions.
• --arg-from-file ⟨#opt-arg-from-file⟩ name path
Pass the contents of file path as the argument name to Nix functions.
• --arg-from-stdin ⟨#opt-arg-from-stdin⟩ name
Pass the contents of stdin as the argument name to Nix functions.
• --argstr ⟨#opt-argstr⟩ name string
Pass the string string as the argument name to Nix functions.
• --debugger ⟨#opt-debugger⟩
Start an interactive environment if evaluation fails.
• --eval-store ⟨#opt-eval-store⟩ store-url
The URL of the Nix store ⟨@docroot@/store/types/index.md#store-url-format⟩ to use for evaluation, i.e.
to store derivations (.drv files) and inputs referenced by them.
• --impure ⟨#opt-impure⟩
Allow access to mutable paths and repositories.
• --include ⟨#opt-include⟩ / -I path
Add path to search path entries used to resolve lookup paths ⟨@docroot@/language/constructs/lookup-
path.md⟩
This option may be given multiple times.
Paths added through -I take precedence over the nix-path configuration setting ⟨@docroot@/command-
ref/conf-file.md#conf-nix-path⟩ and the NIX_PATH environment variable ⟨@docroot@/command-ref/env-
common.md#env-NIX_PATH⟩.
• --override-flake ⟨#opt-override-flake⟩ original-ref resolved-ref
Override the flake registries, redirecting original-ref to resolved-ref.
Common flake-related options
• --commit-lock-file ⟨#opt-commit-lock-file⟩
Commit changes to the flake’s lock file.
• --inputs-from ⟨#opt-inputs-from⟩ flake-url
Use the inputs of the specified flake as registry entries.
• --no-registries ⟨#opt-no-registries⟩
Don’t allow lookups in the flake registries.
DEPRECATED
Use --no-use-registries ⟨#opt-no-use-registries⟩ instead.
• --no-update-lock-file ⟨#opt-no-update-lock-file⟩
Do not allow any updates to the flake’s lock file.
• --no-write-lock-file ⟨#opt-no-write-lock-file⟩
Do not write the flake’s newly generated lock file.
• --output-lock-file ⟨#opt-output-lock-file⟩ flake-lock-path
Write the given lock file instead of flake.lock within the top-level flake.
• --override-input ⟨#opt-override-input⟩ input-path flake-url
Override a specific flake input (e.g. dwarffs/nixpkgs). This implies --no-write-lock-file.
• --recreate-lock-file ⟨#opt-recreate-lock-file⟩
Recreate the flake’s lock file from scratch.
DEPRECATED
Use nix flake update ⟨@docroot@/command-ref/new-cli/nix3-flake-update.md⟩ instead.
• --reference-lock-file ⟨#opt-reference-lock-file⟩ flake-lock-path
Read the given lock file instead of flake.lock within the top-level flake.
• --update-input ⟨#opt-update-input⟩ input-path
Update a specific flake input (ignoring its previous entry in the lock file).
DEPRECATED
Use nix flake update ⟨@docroot@/command-ref/new-cli/nix3-flake-update.md⟩ instead.
Logging-related options
• --debug ⟨#opt-debug⟩
Set the logging verbosity level to ‘debug’.
• --log-format ⟨#opt-log-format⟩ format
Set the format of log output; one of raw, internal-json, bar or bar-with-logs.
• --print-build-logs ⟨#opt-print-build-logs⟩ / -L
Print full build logs on standard error.
• --quiet ⟨#opt-quiet⟩
Decrease the logging verbosity level.
• --verbose ⟨#opt-verbose⟩ / -v
Increase the logging verbosity level.
Miscellaneous global options
• --help ⟨#opt-help⟩
Show usage information.
• --offline ⟨#opt-offline⟩
Disable substituters and consider all previously downloaded files up-to-date.
• --option ⟨#opt-option⟩ name value
Set the Nix configuration setting name to value (overriding nix.conf).
• --refresh ⟨#opt-refresh⟩
Consider all previously downloaded files out-of-date.
• --repair ⟨#opt-repair⟩
During evaluation, rewrite missing or corrupted files in the Nix store. During building, rebuild
missing or corrupted store paths.
• --version ⟨#opt-version⟩
Show version information.
Options that change the interpretation of installables
• --expr ⟨#opt-expr⟩ expr
Interpret installables ⟨@docroot@/command-ref/new-cli/nix.md#installables⟩ as attribute paths relative
to the Nix expression expr.
• --file ⟨#opt-file⟩ / -f file
Interpret installables ⟨@docroot@/command-ref/new-cli/nix.md#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 ⟨@docroot@/command-ref/conf-file.md#command-line-flags⟩ for overriding configuration
settings with command line flags.
nix3-print-dev-env(1)