From 8785bd7759df7ba9c199dcdf398edd922866e3df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Thu, 21 Dec 2017 22:12:00 +0100 Subject: [PATCH] doc: Document fixed-output derivations. * doc/guix.texi (Derivations): Add paragraph on fixed-output derivations. --- doc/guix.texi | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/doc/guix.texi b/doc/guix.texi index 6b6f8dedae..faad3ad6bb 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -4210,6 +4210,14 @@ paths}. Derivations paths can be passed to the @code{build-derivations} procedure to perform the build actions they prescribe (@pxref{The Store}). +@cindex fixed-output derivations +Operations such as file downloads and version-control checkouts for +which the expected content hash is known in advance are modeled as +@dfn{fixed-output derivations}. Unlike regular derivations, the outputs +of a fixed-output derivation are independent of its inputs---e.g., a +source code download produces the same result regardless of the download +method and tools being used. + The @code{(guix derivations)} module provides a representation of derivations as Scheme objects, along with procedures to create and otherwise manipulate derivations. The lowest-level primitive to create