Technical Notes

Manpages - nix3-develop.1

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

#+end_quote

Name

nix develop - run a bash shell that provides the build environment of a derivation

Synopsis

nix develop [/option/…] installable

Examples

  • Start a shell with the build environment of the default package of the flake in the current directory:
# nix develop

Typical commands to run inside this shell are:

# configurePhase
# buildPhase
# installPhase

Alternatively, you can run whatever build tools your project uses directly, e.g. for a typical Unix project:

# ./configure --prefix=$out
# make
# make install
  • Run a particular build phase directly:
# nix develop --unpack
# nix develop --configure
# nix develop --build
# nix develop --check
# nix develop --install
# nix develop --installcheck
  • Start a shell with the build environment of GNU Hello:
# nix develop nixpkgs#hello
  • Record a build environment in a profile:
# nix develop --profile /tmp/my-build-env nixpkgs#hello
  • Use a build environment previously recorded in a profile:
# nix develop /tmp/my-build-env
  • Replace all occurrences of the store path corresponding to glibc.dev with a writable directory:
# nix develop --redirect nixpkgs#glibc.dev ~/my-glibc/outputs/dev

Note that this is useful if you're running a nix develop shell for nixpkgs#glibc in ~/my-glibc and want to compile another package against it.

  • Run a series of script commands:
# nix develop --command bash -c "mkdir build && cmake .. && make"

Description

nix develop starts a bash shell that provides an interactive build environment nearly identical to what Nix would use to build installable. Inside this shell, environment variables and shell functions are set up so that you can interactively and incrementally build your package.

Nix determines the build environment by building a modified version of the derivation installable that just records the environment initialised by stdenv and exits. This build environment can be recorded into a profile using --profile.

The prompt used by the bash shell can be customised by setting the bash-prompt, bash-prompt-prefix, and bash-prompt-suffix settings in nix.conf or in the flake's nixConfig attribute.

Flake output attributes

If no flake output attribute is given, nix develop tries the following flake output attributes:

  • devShells.<system>.default
  • packages.<system>.default

If a flake output name is given, nix develop tries the following flake output attributes:

  • devShells.<system>.<name>
  • packages.<system>.<name>
  • legacyPackages.<system>.<name>

Options

  • --build Run the build phase.
  • --check Run the check phase.
  • --command / -c command args Instead of starting an interactive shell, start the specified command and arguments.
  • --configure Run the configure phase.
  • --ignore-environment / -i Clear the entire environment (except those specified with --keep).
  • --install Run the install phase.
  • --installcheck Run the installcheck phase.
  • --keep / -k name Keep the environment variable name.
  • --phase phase-name The stdenv phase to run (e.g. build or configure).
  • --profile path The profile to operate on.
  • --redirect installable outputs-dir Redirect a store path to a mutable location.
  • --unpack Run the unpack phase.
  • --unset / -u name Unset the environment variable name.

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.