guix style command helps users and packagers alike style
their package definitions and configuration files according to the
latest fashionable trends. It can either reformat whole files, with the
--whole-file option, or apply specific styling rules to
individual package definitions. The command currently provides the
following styling rules:
The way package inputs are written is going through a transition
package Reference, for more on package inputs). Until version
1.3.0, package inputs were written using the “old style”, where each
input was given an explicit label, most of the time the package name:
(package ;; … ;; The "old style" (deprecated). (inputs `(("libunistring" ,libunistring) ("libffi" ,libffi))))
Today, the old style is deprecated and the preferred style looks like this:
Likewise, uses of
alist-delete and friends to manipulate inputs
is now deprecated in favor of
modify-inputs (see Defining Package Variants, for more info on
In the vast majority of cases, this is a purely mechanical change on the
surface syntax that does not even incur a package rebuild. Running
guix style -S inputs can do that for you, whether you’re working on
packages in Guix proper or in an external channel.
The general syntax is:
guix style [options] package…
guix style to analyze and rewrite the definition
of package… or, when package is omitted, of all
the packages. The --styling or -S option allows you
to select the style rule, the default rule being
To reformat entire source files, the syntax is:
guix style --whole-file file…
The available options are listed below.
Show source file locations that would be edited but do not modify them.
Reformat the given files in their entirety. In that case, subsequent arguments are interpreted as file names (rather than package names), and the --styling option has no effect.
As an example, here is how you might reformat your operating system configuration (you need write permissions for the file):
guix style -f /etc/config.scm
Apply rule, one of the following styling rules:
Format the given package definition(s)—this is the default styling rule. For example, a packager running Guix on a checkout (see Running Guix Before It Is Installed) might want to reformat the definition of the Coreutils package like so:
./pre-inst-env guix style coreutils
Rewrite package inputs to the “new style”, as described above. This
is how you would rewrite inputs of package
whatnot in your own
guix style -L ~/my/channel -S inputs whatnot
Rewriting is done in a conservative way: preserving comments and bailing out if it cannot make sense of the code that appears in an inputs field. The --input-simplification option described below provides fine-grain control over when inputs should be simplified.
Rewrite package arguments to use G-expressions (see G-Expressions). For example, consider this package definition:
(define-public my-package (package ;; … (arguments ;old-style quoted arguments '(#:make-flags '("V=1") #:phases (modify-phases %standard-phases (delete 'build))))))
guix style -S arguments on this package would rewrite
arguments field like to:
(define-public my-package (package ;; … (arguments (list #:make-flags #~'("V=1") #:phases #~(modify-phases %standard-phases (delete 'build))))))
Note that changes made by the
arguments rule do not entail a
rebuild of the affected packages. Furthermore, if a package definition
happens to be using G-expressions already,
guix style leaves
List and describe the available styling rules and exit.
Add directory to the front of the package module search path (see Package Modules).
Style the package expr evaluates to.
For example, running:
guix style -e '(@ (gnu packages gcc) gcc-5)'
gcc-5 package definition.
When using the
inputs styling rule, with ‘-S inputs’, this
option specifies the package input simplification policy for cases where
an input label does not match the corresponding package name.
policy may be one of the following:
Simplify inputs only when the change is “silent”, meaning that the package does not need to be rebuilt (its derivation is unchanged).
Simplify inputs only when that is “safe” to do: the package might need to be rebuilt, but the change is known to have no observable effect.
Simplify inputs even when input labels do not match package names, and even if that might have an observable effect.
The default is
silent, meaning that input simplifications do not
trigger any package rebuild.