nix develop - Lix Reference Manual

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

# Name

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

# Synopsis

`nix develop` [option...] installable

Note: this command's interface is based heavily around installables, which you may want to read about first (`nix --help`).

# 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 Lix 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.

- `--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 the Nix search path. The Nix search path is initialized from the colon-separated `NIX_PATH` environment variable, and is used to look up the location of Nix expressions using paths enclosed in angle brackets (i.e., `<nixpkgs>`).

  For instance, passing

      -I /home/eelco/Dev
      -I /etc/nixos

  will cause Lix to look for paths relative to `/home/eelco/Dev` and `/etc/nixos`, in that order. This is equivalent to setting the `NIX_PATH` environment variable to

      /home/eelco/Dev:/etc/nixos

  It is also possible to match paths against a prefix. For example, passing

      -I nixpkgs=/home/eelco/Dev/nixpkgs-branch
      -I /etc/nixos

  will cause Lix to search for `<nixpkgs/path>` in `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`.

  If a path in the Nix search path starts with `http://` or `https://`, it is interpreted as the URL of a tarball that will be downloaded and unpacked to a temporary location. The tarball must consist of a single top-level directory. For example, passing

      -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz

  tells Lix to download and use the current contents of the `master` branch in the `nixpkgs` repository.

  The URLs of the tarballs from the official `nixos.org` channels (see the manual page for `nix-channel`) can be abbreviated as `channel:<channel-name>`. For instance, the following two flags are equivalent:

      -I nixpkgs=channel:nixos-21.05
      -I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz

  You can also fetch source trees using flake URLs and add them to the search path. For instance,

      -I nixpkgs=flake:nixpkgs

  specifies that the prefix `nixpkgs` shall refer to the source tree downloaded from the `nixpkgs` entry in the flake registry. Similarly,

      -I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05

  makes `<nixpkgs>` refer to a particular branch of the `NixOS/nixpkgs` repository on GitHub.

- `--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.

- `--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`.

- `--reference-lock-file` flake-lock-path Read the given lock file instead of `flake.lock` within the top-level flake.

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`, `bar-with-logs`, `multiline` or `multiline-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 Lix 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` / `-E` 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.