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Diffstat (limited to 'doc/guix.texi')
-rw-r--r-- | doc/guix.texi | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index b1a1e71055..31b8cd7069 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -6848,6 +6848,47 @@ cross-compiling: It is an error to refer to @code{this-package} outside a package definition. @end deffn +@cindex development inputs, of a package +@cindex implicit inputs, of a package +Sometimes you will want to obtain the list of inputs needed to +@emph{develop} a package---all the inputs that are visible when the +package is compiled. This is what the @code{package-development-inputs} +procedure returns. + +@deffn {Scheme Procedure} package-development-inputs @var{package} @ + [@var{system}] [#:target #f] +Return the list of inputs required by @var{package} for development +purposes on @var{system}. When @var{target} is true, return the inputs +needed to cross-compile @var{package} from @var{system} to +@var{triplet}, where @var{triplet} is a triplet such as +@code{"aarch64-linux-gnu"}. + +Note that the result includes both explicit inputs and implicit +inputs---inputs automatically added by the build system (@pxref{Build +Systems}). Let us take the @code{hello} package to illustrate that: + +@lisp +(use-modules (gnu packages base) (guix packages)) + +hello +@result{} #<package hello@@2.10 gnu/packages/base.scm:79 7f585d4f6790> + +(package-direct-inputs hello) +@result{} () + +(package-development-inputs hello) +@result{} (("source" @dots{}) ("tar" #<package tar@@1.32 @dots{}>) @dots{}) +@end lisp + +In this example, @code{package-direct-inputs} returns the empty list, +because @code{hello} has zero explicit dependencies. Conversely, +@code{package-development-inputs} includes inputs implicitly added by +@code{gnu-build-system} that are required to build @code{hello}: tar, +gzip, GCC, libc, Bash, and more. To visualize it, @command{guix graph +hello} would show you explicit inputs, whereas @command{guix graph -t +bag hello} would include implicit inputs (@pxref{Invoking guix graph}). +@end deffn + Because packages are regular Scheme objects that capture a complete dependency graph and associated build procedures, it is often useful to write procedures that take a package and return a modified version |