64/155: doc: Document 'cargo-build-system'.

[John Darrington]

jmd pushed a commit to branch wip-installer
in repository guix.

commit 0703f24702a4d4566b0d9be3b8fce8980a021275
Author: Ludovic Courtès <address@hidden>
Date:   Sun Dec 18 16:55:05 2016 +0100

    doc: Document 'cargo-build-system'.
    
    * doc/guix.texi (Build Systems): Add 'cargo-build-system'.
---
 doc/guix.texi |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/doc/guix.texi b/doc/guix.texi
index 5d3a175..3b2368b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -3187,6 +3187,19 @@ which file the system is defined in.
 
 @end defvr
 
address@hidden {Scheme Variable} cargo-build-system
address@hidden Rust programming language
address@hidden Cargo (Rust build system)
+This variable is exported by @code{(guix build-system cargo)}.  It
+supports builds of packages using Cargo, the build tool of the
address@hidden://www.rust-lang.org, Rust programming language}.
+
+In its @code{configure} phase, this build system replaces dependencies
+specified in the @file{Carto.toml} file with inputs to the Guix package.
+The @code{install} phase installs the binaries, and it also installs the
+source code and @file{Cargo.toml} file.
address@hidden defvr
+
 @defvr {Scheme Variable} cmake-build-system
 This variable is exported by @code{(guix build-system cmake)}.  It
 implements the build procedure for packages using the