guix environment, Up: Development [Contents][Index]
The purpose of
guix shell is to make it easy to create one-off
software environments, without changing one’s profile. It is typically
used to create development environments; it is also a convenient way to
run applications without “polluting” your profile.
guix shellcommand was recently introduced to supersede
guix environment(see Invoking
guix environment). If you are familiar with
guix environment, you will notice that it is similar but also—we hope!—more convenient.
The general syntax is:
guix shell [options] [package…]
The following example creates an environment containing Python and NumPy,
building or downloading any missing package, and runs the
python3 command in that environment:
guix shell python python-numpy -- python3
guix shellcan be also be used as a script interpreter, also known as shebang. Here is an example self-contained Python script making use of this feature:#!/usr/bin/env -S guix shell python python-numpy -- python3 import numpy print("This is numpy", numpy.version.version)
You may pass any
guix shelloption, but there’s one caveat: the Linux kernel has a limit of 127 bytes on shebang length.
Development environments can be created as in the example below, which spawns an interactive shell containing all the dependencies and environment variables needed to work on Inkscape:
guix shell --development inkscape
Exiting the shell places the user back in the original environment
guix shell was invoked. The next garbage collection
guix gc) may clean up packages that were installed in
the environment and that are no longer used outside of it.
As an added convenience,
guix shell will try to do what you
mean when it is invoked interactively without any other arguments
If it finds a manifest.scm in the current working directory or
any of its parents, it uses this manifest as though it was given via
Likewise, if it finds a guix.scm in the same directories, it uses
it to build a development profile as though both
--file were present.
In either case, the file will only be loaded if the directory it
resides in is listed in
This provides an easy way to define, share, and enter development
By default, the shell session or command runs in an augmented
environment, where the new packages are added to search path environment
variables such as
PATH. You can, instead, choose to create an
isolated environment containing nothing but the packages you
asked for. Passing the --pure option clears environment
variable definitions found in the parent environment14; passing --container goes one step further by
spawning a container isolated from the rest of the system:
guix shell --container emacs gcc-toolchain
The command above spawns an interactive shell in a container where
gcc-toolchain, and their dependencies
is available. The container lacks network access and shares no files
other than the current working directory with the surrounding
environment. This is useful to prevent access to system-wide resources
such as /usr/bin on foreign distros.
This --container option can also prove useful if you wish to
run a security-sensitive application, such as a web browser, in an
isolated environment. For example, the command below launches
Ungoogled-Chromium in an isolated environment, this time sharing network
access with the host and preserving its
variable, but without even sharing the current directory:
guix shell --container --network --no-cwd ungoogled-chromium \ --preserve='^DISPLAY$' -- chromium
guix shell defines the
variable in the shell it spawns; its value is the file name of the
profile of this environment. This allows users to, say, define a
specific prompt for development environments in their .bashrc
(see Bash Startup Files in The GNU Bash Reference Manual):
if [ -n "$GUIX_ENVIRONMENT" ] then export PS1="\u@\h \w [dev]\$ " fi
... or to browse the profile:
$ ls "$GUIX_ENVIRONMENT/bin"
The available options are summarized below.
Set up the environment and check whether the shell would clobber
environment variables. It’s a good idea to use this option the first
time you run
guix shell for an interactive session to make
sure your setup is correct.
For example, if the shell modifies the
PATH environment variable,
report it since you would get a different environment than what you
Such problems usually indicate that the shell startup files are unexpectedly modifying those environment variables. For example, if you are using Bash, make sure that environment variables are set or modified in ~/.bash_profile and not in ~/.bashrc—the former is sourced only by log-in shells. See Bash Startup Files in The GNU Bash Reference Manual, for details on Bash start-up files.
guix shell to include in the environment the
dependencies of the following package rather than the package itself.
This can be combined with other packages. For instance, the command
below starts an interactive shell containing the build-time dependencies
of GNU Guile, plus Autoconf, Automake, and Libtool:
guix shell -D guile autoconf automake libtool
Create an environment for the package or list of packages that expr evaluates to.
For example, running:
guix shell -D -e '(@ (gnu packages maths) petsc-openmpi)'
starts a shell with the environment for this specific variant of the PETSc package.
guix shell -e '(@ (gnu) %base-packages)'
starts a shell with all the base system packages available.
The above commands only use the default output of the given packages. To select other outputs, two element tuples can be specified:
guix shell -e '(list (@ (gnu packages bash) bash) "include")'
package->development-manifest, for information on how to write a
manifest for the development environment of a package.
Create an environment containing the package or list of packages that the code within file evaluates to.
As an example, file might contain a definition like this (see Defining Packages):
(use-modules (guix) (gnu packages gdb) (gnu packages autotools) (gnu packages texinfo)) ;; Augment the package definition of GDB with the build tools ;; needed when developing GDB (and which are not needed when ;; simply installing it.) (package (inherit gdb) (native-inputs (modify-inputs (package-native-inputs gdb) (prepend autoconf-2.64 automake texinfo))))
With the file above, you can enter a development environment for GDB by running:
guix shell -D -f gdb-devel.scm
Create an environment for the packages contained in the manifest object returned by the Scheme code in file. This option can be repeated several times, in which case the manifests are concatenated.
This is similar to the same-named option in
(see --manifest) and uses the same
See Writing Manifests, for information on how to write a manifest. See --export-manifest below on how to obtain a first manifest.
Write to standard output a manifest suitable for --manifest corresponding to given command-line options.
This is a way to “convert” command-line arguments into a manifest. For example, imagine you are tired of typing long lines and would like to get a manifest equivalent to this command line:
guix shell -D guile git emacs emacs-geiser emacs-geiser-guile
Just add --export-manifest to the command line above:
guix shell --export-manifest \ -D guile git emacs emacs-geiser emacs-geiser-guile
... and you get a manifest along these lines:
(concatenate-manifests (list (specifications->manifest (list "git" "emacs" "emacs-geiser" "emacs-geiser-guile")) (package->development-manifest (specification->package "guile"))))
You can store it into a file, say manifest.scm, and from there
pass it to
guix shell or indeed pretty much any
guix shell -m manifest.scm
Voilà, you’ve converted a long command line into a manifest! That conversion process honors package transformation options (see Package Transformation Options) so it should be lossless.
Create an environment containing the packages installed in profile.
guix package (see Invoking
guix package) to create
and manage profiles.
Unset existing environment variables when building the new environment, except those specified with --preserve (see below). This has the effect of creating an environment in which search paths only contain package inputs.
When used alongside --pure, preserve the environment variables matching regexp—in other words, put them on a “white list” of environment variables that must be preserved. This option can be repeated several times.
guix shell --pure --preserve=^SLURM openmpi … \ -- mpirun …
This example runs
mpirun in a context where the only environment
variables defined are
PATH, environment variables whose name starts
with ‘SLURM’, as well as the usual “precious” variables (
Display the environment variable definitions that make up the environment.
Attempt to build for system—e.g.,
Run command within an isolated container. The current working directory outside the container is mapped inside the container. Additionally, unless overridden with --user, a dummy home directory is created that matches the current user’s home directory, and /etc/passwd is configured accordingly.
The spawned process runs as the current user outside the container. Inside the container, it has the same UID and GID as the current user, unless --user is passed (see below).
For containers, share the network namespace with the host system. Containers created without this flag only have access to the loopback device.
For containers, link the environment profile to ~/.guix-profile
within the container and set
GUIX_ENVIRONMENT to that.
This is equivalent to making ~/.guix-profile a symlink to the
actual profile within the container.
Linking will fail and abort the environment if the directory already
exists, which will certainly be the case if
was invoked in the user’s home directory.
Certain packages are configured to look in ~/.guix-profile for configuration files and data;15 --link-profile allows these programs to behave as expected within the environment.
For containers, use the username user in place of the current user. The generated /etc/passwd entry within the container will contain the name user, the home directory will be /home/user, and no user GECOS data will be copied. Furthermore, the UID and GID inside the container are 1000. user need not exist on the system.
Additionally, any shared or exposed path (see --share and --expose respectively) whose target is within the current user’s home directory will be remapped relative to /home/USER; this includes the automatic mapping of the current working directory.
# will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target cd $HOME/wd guix shell --container --user=foo \ --expose=$HOME/test \ --expose=/tmp/target=$HOME/target
While this will limit the leaking of user identity through home paths and each of the user fields, this is only one useful component of a broader privacy/anonymity solution—not one in and of itself.
For containers, the default behavior is to share the current working directory with the isolated container and immediately change to that directory within the container. If this is undesirable, --no-cwd will cause the current working directory to not be automatically shared and will change to the user’s home directory within the container instead. See also --user.
For containers, --expose (resp. --share) exposes the file system source from the host system as the read-only (resp. writable) file system target within the container. If target is not specified, source is used as the target mount point in the container.
The example below spawns a Guile REPL in a container in which the user’s home directory is accessible read-only via the /exchange directory:
guix shell --container --expose=$HOME=/exchange guile -- guile
For containers, create the symbolic links specified by spec, as documented in pack-symlink-option.
When used with --container, emulate a Filesystem Hierarchy Standard (FHS) configuration within the container, providing /bin, /lib, and other directories and files specified by the FHS.
As Guix deviates from the FHS specification, this option sets up the container to more closely mimic that of other GNU/Linux distributions. This is useful for reproducing other development environments, testing, and using programs which expect the FHS specification to be followed. With this option, the container will include a version of glibc that will read /etc/ld.so.cache within the container for the shared library cache (contrary to glibc in regular Guix usage) and set up the expected FHS directories: /bin, /etc, /lib, and /usr from the container’s profile.
When used with --container, provide Guix inside the container and arrange so that it can interact with the build daemon that runs outside the container. This is useful if you want, within your isolated container, to create other containers, as in this sample session:
$ guix shell -CW coreutils [env]$ guix shell -C guile -- guile -c '(display "hello!\n")' hello! [env]$ exit
The session above starts a container with
PATH. From there, we spawn
guix shell to
create a nested container that provides nothing but Guile.
Another example is evaluating a guix.scm file that is untrusted, as shown here:
guix shell -CW -- guix build -f guix.scm
guix build command as executed above can only access the
Under the hood, the -W option does several things:
guixinvocations are visible;
guixcommand to the profile in the container, such that
guix describereturns the same state inside and outside the container;
In most cases,
guix shell caches the environment so that
subsequent uses are instantaneous. Least-recently used cache entries
are periodically removed. The cache is also invalidated, when using
--file or --manifest, anytime the corresponding file
The --rebuild-cache forces the cached environment to be
refreshed. This is useful when using --file or
--manifest and the
file has external dependencies, or if its behavior depends, say, on
Make file a symlink to the profile for this environment, and register it as a garbage collector root.
This is useful if you want to protect your environment from garbage collection, to make it “persistent”.
When this option is omitted,
guix shell caches profiles so
that subsequent uses of the same environment are instantaneous—this is
comparable to using --root except that
takes care of periodically removing the least-recently used garbage
In some cases,
guix shell does not cache profiles—e.g., if
transformation options such as --with-latest are used. In
those cases, the environment is protected from garbage collection only
for the duration of the
guix shell session. This means that
next time you recreate the same environment, you could have to rebuild
or re-download packages.
guix gc, for more on GC roots.
guix shell also supports all of the common build options that
guix build supports (see Common Build Options) as well as
package transformation options (see Package Transformation Options).
Be sure to
use the --check option the first time you use
shell interactively to make sure the shell does not undo the effect of
For example, the
fontconfig package inspects ~/.guix-profile/share/fonts
for additional fonts.
guix environment, Up: Development [Contents][Index]