doc: Move most 'HACKING' informations into the manual.

* HACKING (Contributing): New section.
  (Building from Git, The Perfect Setup, Coding Style, Submitting Patches):
  Move to ...
* doc/guix.texi (Running Guix Before It Is Installed): Likewise.
* doc/contributing.texi: ... here. New file.
* doc.am (EXTRA_DIST): Use it.
* README (Installation): Adapt to it.
* configure.ac (DOT): Likewise.

6 files changed, 244 insertions, 185 deletions

diff --git a/HACKING b/HACKING
index 1e742c8454..41838ee816 100644
--- a/HACKING
+++ b/HACKING
@@ -2,141 +2,20 @@
 
 #+TITLE: Hacking GNU Guix and Its Incredible Distro
 
-Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
-Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
-Copyright © 2014 Pierre-Antoine Rault <par@rigelk.eu>
+Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+Copyright © 2015 Mathieu Lirzin <mthl@openmailbox.org>
 
   Copying and distribution of this file, with or without modification,
   are permitted in any medium without royalty provided the copyright
   notice and this notice are preserved.
 
+* Contributing
 
-* Building from Git
+See the manual for useful hacking informations, either by running
 
-When building Guix from a checkout, the following packages are required in
-addition to those mentioned in the installation instructions:
+  info -f doc/guix.info "(guix) Contributing"
 
-  - [[http://www.gnu.org/software/autoconf/][GNU Autoconf]]
-  - [[http://www.gnu.org/software/automake/][GNU Automake]]
-  - [[http://www.gnu.org/software/gettext/][GNU Gettext]]
-  - [[http://www.graphviz.org/][Graphviz]]
-  - [[http://www.gnu.org/software/help2man/][GNU Help2man]] (optional)
-
-Run ‘./bootstrap’ to download the Nix daemon source code and to generate the
-build system infrastructure using autoconf.  It reports an error if an
-inappropriate version of the above packages is being used.
-
-If you get an error like this one:
-
-  configure.ac:46: error: possibly undefined macro: PKG_CHECK_MODULES
-
-it probably means that Autoconf couldn’t find ‘pkg.m4’, which is provided by
-pkg-config.  Make sure that ‘pkg.m4’ is available.  For instance, if you
-installed Automake in ‘/usr/local’, it wouldn’t look for ‘.m4’ files in
-‘/usr/share’.  So you have to invoke the following command in that case
-
-  $ export ACLOCAL_PATH=/usr/share/aclocal
-
-See “info '(automake) Macro Search Path'” for more information.
-
-Then, run ‘./configure’ as usual.
-
-Finally, you have to invoke ‘make check’ to run tests.  If anything fails,
-take a look at “info '(guix) Installation'” or send a message to
-<guix-devel@gnu.org>.
-
-* Running Guix before it is installed
-
-See the same-named section in the manual.
-
-* The Perfect Setup
-
-The Perfect Setup to hack on Guix is basically the perfect setup used
-for Guile hacking (info "(guile) Using Guile in Emacs").  First, you
-need more than an editor, you need [[http://www.gnu.org/software/emacs][Emacs]], empowered by the wonderful
-[[http://nongnu.org/geiser/][Geiser]].
-
-Geiser allows for interactive and incremental development from within
-Emacs: code compilation and evaluation from within buffers, access to
-on-line documentation (docstrings), context-sensitive completion, M-. to
-jump to an object definition, a REPL to try out your code, and more.
-
-To actually edit the code, Emacs already has a neat Scheme mode.  But in
-addition to that, you must not miss [[http://www.emacswiki.org/emacs/ParEdit][Paredit]].  It provides facilities to
-directly operate on the syntax tree, such as raising an s-expression or
-wrapping it, swallowing or rejecting the following s-expression, etc.
-
-* Submitting Patches
-
-Development is done using the Git distributed version control system.  Thus,
-access to the repository is not strictly necessary.  We welcome contributions
-in the form of patches as produced by ‘git format-patch’ sent to
-guix-devel@gnu.org.  Please write commit logs in the [[http://www.gnu.org/prep/standards/html_node/Change-Logs.html#Change-Logs][GNU ChangeLog
-format]]; you can check the commit history for examples.
-
-Before submitting a patch that adds or modifies a package definition, please
-run ‘guix lint PACKAGE’, where PACKAGE is the name of the new or modified
-package, and fix any errors it reports.  In addition, please make sure the
-package builds on your platform, using ‘guix build’.  You may also want to
-check that dependent package (if applicable) are not affected by the change;
-‘guix refresh --list-dependent PACKAGE’ will help you do that.
-
-When posting a patch to the mailing list, use "[PATCH] ..." as a subject.  You
-may use your email client or the ‘git send-mail’ command.
-
-As you become a regular contributor, you may find it convenient to have write
-access to the repository (see below.)
-
-* Coding Style
-
-In general our code follows the [[info:standards][GNU Coding Standards]] (GCS).  However, the GCS
-do not say much about Scheme, so here are some additional rules.
-
-** Programming Paradigm
-
-Scheme code in Guix is written in a purely functional style.  One exception is
-code that involves input/output, and procedures that implement low-level
-concepts, such as the ‘memoize’ procedure.
-
-** Modules
-
-Guile modules that are meant to be used on the builder side must live in the
-(guix build …) name space.  They must not refer to other Guix or GNU modules.
-However, it is OK for a “host-side” module to use a build-side module.
-
-Modules that deal with the broader GNU system should be in the (gnu …) name
-space rather than (guix …).
-
-** Data Types and Pattern Matching
-
-The tendency in classical Lisp is to use lists to represent everything, and
-then to browse them “by hand” using ‘car’, ‘cdr’, ‘cadr’, and co.  There are
-several problems with that style, notably the fact that it is hard to read,
-error-prone, and a hindrance to proper type error reports.
-
-Guix code should define appropriate data types (for instance, using
-‘define-record-type*’) rather than abuse lists.  In addition, it should use
-pattern matching, via Guile’s (ice-9 match) module, especially when matching
-lists.
-
-** Formatting Code
-
-When writing Scheme code, we follow common wisdom among Scheme programmers.
-In general, we follow the [[http://mumble.net/~campbell/scheme/style.txt][Riastradh's Lisp Style Rules]].  This document happens
-to describe the conventions mostly used in Guile’s code too.  It is very
-thoughtful and well written, so please do read it.
-
-Some special forms introduced in Guix, such as the ‘substitute*’ macro, have
-special indentation rules.  These are defined in the .dir-locals.el file,
-which Emacs automatically uses.  If you do not use Emacs, please make sure to
-let your editor know the rules.
-
-We require all top-level procedures to carry a docstring.  This requirement
-can be relaxed for simple private procedures in the (guix build …) name space,
-though.
-
-Procedures should not have more than four positional parameters.  Use keyword
-parameters for procedures that take more than four parameters.
+or by checking the [[http://www.gnu.org/software/guix/manual/guix.html#Contributing][web copy of the manual]].
 
 * Commit Access
 
diff --git a/README b/README
index 4d3367ed8f..df528222e9 100644
--- a/README
+++ b/README
@@ -46,8 +46,8 @@ See the manual for the installation instructions, either by running
 
 or by checking the [[http://www.gnu.org/software/guix/manual/guix.html#Installation][web copy of the manual]].
 
-For information on installation from a Git checkout, please see the ‘HACKING’
-file.
+For information on installation from a Git checkout, please see the section
+"Building from Git" in the manual.
 
 * Installing Guix from Guix
 
diff --git a/configure.ac b/configure.ac
index 50b65fdac1..2c8b9f076c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -179,7 +179,7 @@ AC_CACHE_SAVE
 m4_include([config-daemon.ac])
 
 dnl `dot' (from the Graphviz package) is only needed for maintainers.
-dnl See `HACKING' for more info.
+dnl See `Building from Git' in the manual for more info.
 AM_MISSING_PROG([DOT], [dot])
 
 dnl Manual pages.
diff --git a/doc.am b/doc.am
index 14343ceacb..de232a87a4 100644
--- a/doc.am
+++ b/doc.am
@@ -19,6 +19,7 @@
 
 info_TEXINFOS = doc/guix.texi
 EXTRA_DIST +=					\
+  doc/contributing.texi				\
   doc/emacs.texi				\
   doc/fdl-1.3.texi				\
   doc/images/bootstrap-graph.dot		\
diff --git a/doc/contributing.texi b/doc/contributing.texi
new file mode 100644
index 0000000000..536f223da4
--- /dev/null
+++ b/doc/contributing.texi
@@ -0,0 +1,216 @@
+@node Contributing
+@chapter Contributing
+
+This project is a cooperative effort, and we need your help to make it
+grow!  Please get in touch with us on @email{guix-devel@@gnu.org} and
+@code{#guix} on the Freenode IRC network.  We welcome ideas, bug
+reports, patches, and anything that may be helpful to the project.  We
+particularly welcome help on packaging (@pxref{Packaging Guidelines}).
+
+@menu
+* Building from Git::           The latest and greatest.
+* Running Guix Before It Is Installed::  Hacker tricks.
+* The Perfect Setup::           The right tools.
+* Coding Style::                Hygiene of the contributor.
+* Submitting Patches::          Share your work.
+@end menu
+
+@node Building from Git
+@section Building from Git
+
+If you want to hack Guix itself, it is recommended to use the latest
+version from the Git repository.  When building Guix from a checkout,
+the following packages are required in addition to those mentioned in
+the installation instructions (@pxref{Requirements}).
+
+@itemize
+@item @url{http://gnu.org/software/autoconf/, GNU Autoconf};
+@item @url{http://gnu.org/software/automake/, GNU Automake};
+@item @url{http://gnu.org/software/gettext/, GNU Gettext};
+@item @url{http://www.graphviz.org/, Graphviz};
+@item @url{http://www.gnu.org/software/help2man/, GNU Help2man (optional)}.
+@end itemize
+
+Run @command{./bootstrap} to download the Nix daemon source code and to
+generate the build system infrastructure using autoconf.  It reports an
+error if an inappropriate version of the above packages is being used.
+
+@noindent
+If you get an error like this one:
+
+@example
+configure.ac:46: error: possibly undefined macro: PKG_CHECK_MODULES
+@end example
+
+it probably means that Autoconf couldn’t find @file{pkg.m4}, which is
+provided by @command{pkg-config}.  Make sure that @file{pkg.m4} is
+available.  For instance, if you installed Automake in
+@file{/usr/local}, it wouldn’t look for @file{.m4} files in
+@file{/usr/share}.  So you have to invoke the following command in that
+case
+
+@example
+export ACLOCAL_PATH=/usr/share/aclocal
+@end example
+
+See @pxref{Macro Search Path,,, automake, The GNU Automake Manual} for
+more information.
+
+Then, run @command{./configure} as usual.
+
+Finally, you have to invoke @code{make check} to run tests.  If anything
+fails, take a look at installation instructions (@pxref{Installation})
+or send a message to the @email{guix-devel@@gnu.org, mailing list}.
+
+
+@node Running Guix Before It Is Installed
+@section Running Guix Before It Is Installed
+
+In order to keep a sane working environment, you will find it useful to
+test the changes made in your local source tree checkout without
+actually installing them.  So that you can distinguish between your
+``end-user'' hat and your ``motley'' costume.
+
+To that end, all the command-line tools can be used even if you have not
+run @code{make install}.  To do that, prefix each command with
+@command{./pre-inst-env} (the @file{pre-inst-env} script lives in the
+top build tree of Guix), as in:
+
+@example
+$ sudo ./pre-inst-env guix-daemon --build-users-group=guixbuild
+$ ./pre-inst-env guix build hello
+@end example
+
+@noindent
+Similarly, for a Guile session using the Guix modules:
+
+@example
+$ ./pre-inst-env guile -c '(use-modules (guix utils)) (pk (%current-system))'
+@end example
+
+The @command{pre-inst-env} script sets up all the environment variables
+necessary to support this, including @env{PATH} and @env{GUILE_LOAD_PATH}.
+
+
+@node The Perfect Setup
+@section The Perfect Setup
+
+The Perfect Setup to hack on Guix is basically the perfect setup used
+for Guile hacking (@pxref{Using Guile in Emacs,,, guile, Guile Reference
+Manual}).  First, you need more than an editor, you need
+@url{http://www.gnu.org/software/emacs, Emacs}, empowered by the
+wonderful @url{http://nongnu.org/geiser/, Geiser}.
+
+Geiser allows for interactive and incremental development from within
+Emacs: code compilation and evaluation from within buffers, access to
+on-line documentation (docstrings), context-sensitive completion,
+@kbd{M-.} to jump to an object definition, a REPL to try out your code,
+and more (@pxref{Introduction,,, geiser, Geiser User Manual}).  For
+convenient Guix development, make sure to augment Guile’s load path so
+that it finds source files from your checkout:
+
+@lisp
+;; @r{Assuming the Guix checkout is in ~/src/guix.}
+(add-to-list 'geiser-guile-load-path "~/src/guix")
+@end lisp
+
+To actually edit the code, Emacs already has a neat Scheme mode.  But in
+addition to that, you must not miss
+@url{http://www.emacswiki.org/emacs/ParEdit, Paredit}.  It provides
+facilities to directly operate on the syntax tree, such as raising an
+s-expression or wrapping it, swallowing or rejecting the following
+s-expression, etc.
+
+
+@node Coding Style
+@section Coding Style
+
+In general our code follows the GNU Coding Standards (@pxref{Top,,,
+standards, GNU Coding Standards}).  However, they do not say much about
+Scheme, so here are some additional rules.
+
+@menu
+* Programming Paradigm::        How to compose your elements.
+* Modules::                     Where to store your code?
+* Data Types and Pattern Matching::  Implementing data structures.
+* Formatting Code::             Writing conventions.
+@end menu
+
+@node Programming Paradigm
+@subsection Programming Paradigm
+
+Scheme code in Guix is written in a purely functional style.  One
+exception is code that involves input/output, and procedures that
+implement low-level concepts, such as the @code{memoize} procedure.
+
+@node Modules
+@subsection Modules
+
+Guile modules that are meant to be used on the builder side must live in
+the @code{(guix build @dots{})} name space.  They must not refer to
+other Guix or GNU modules.  However, it is OK for a ``host-side'' module
+to use a build-side module.
+
+Modules that deal with the broader GNU system should be in the
+@code{(gnu @dots{})} name space rather than @code{(guix @dots{})}.
+
+@node Data Types and Pattern Matching
+@subsection Data Types and Pattern Matching
+
+The tendency in classical Lisp is to use lists to represent everything,
+and then to browse them ``by hand'' using @code{car}, @code{cdr},
+@code{cadr}, and co.  There are several problems with that style,
+notably the fact that it is hard to read, error-prone, and a hindrance
+to proper type error reports.
+
+Guix code should define appropriate data types (for instance, using
+@code{define-record-type*}) rather than abuse lists.  In addition, it
+should use pattern matching, via Guile’s @code{(ice-9 match)} module,
+especially when matching lists.
+
+@node Formatting Code
+@subsection Formatting Code
+
+When writing Scheme code, we follow common wisdom among Scheme
+programmers.  In general, we follow the
+@url{http://mumble.net/~campbell/scheme/style.txt, Riastradh's Lisp
+Style Rules}.  This document happens to describe the conventions mostly
+used in Guile’s code too.  It is very thoughtful and well written, so
+please do read it.
+
+Some special forms introduced in Guix, such as the @code{substitute*}
+macro, have special indentation rules.  These are defined in the
+@file{.dir-locals.el} file, which Emacs automatically uses.  If you do
+not use Emacs, please make sure to let your editor know the rules.
+
+We require all top-level procedures to carry a docstring.  This
+requirement can be relaxed for simple private procedures in the
+@code{(guix build @dots{})} name space, though.
+
+Procedures should not have more than four positional parameters.  Use
+keyword parameters for procedures that take more than four parameters.
+
+
+@node Submitting Patches
+@section Submitting Patches
+
+Development is done using the Git distributed version control system.
+Thus, access to the repository is not strictly necessary.  We welcome
+contributions in the form of patches as produced by @code{git
+format-patch} sent to the @email{guix-devel@@gnu.org, mailing list}.
+Please write commit logs in the ChangeLog format (@pxref{Change Logs,,,
+standards, GNU Coding Standards}); you can check the commit history for
+examples.
+
+Before submitting a patch that adds or modifies a package definition,
+please run @code{guix lint @var{package}}, where @var{package} is the
+name of the new or modified package, and fix any errors it reports
+(@pxref{Invoking guix lint}).  In addition, please make sure the package
+builds on your platform, using @code{guix build @var{package}}.  You may
+also want to check that dependent package (if applicable) are not
+affected by the change; @code{guix refresh --list-dependent
+@var{package}} will help you do that (@pxref{Invoking guix refresh}).
+
+When posting a patch to the mailing list, use @samp{[PATCH] @dots{}} as a
+subject.  You may use your email client or the @command{git send-mail}
+command.
diff --git a/doc/guix.texi b/doc/guix.texi
index c70d1000ae..46dccb8e2b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -13,6 +13,8 @@
 Copyright @copyright{} 2012, 2013, 2014, 2015 Ludovic Courtès@*
 Copyright @copyright{} 2013, 2014 Andreas Enge@*
 Copyright @copyright{} 2013 Nikita Karetnikov@*
+Copyright @copyright{} 2015 Mathieu Lirzin@*
+Copyright @copyright{} 2014 Pierre-Antoine Rault@*
 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer
 
 Permission is granted to copy, distribute and/or modify this document
@@ -88,7 +90,6 @@ Installation
 * Running the Test Suite::      Testing Guix.
 * Setting Up the Daemon::       Preparing the build daemon's environment.
 * Invoking guix-daemon::        Running the build daemon.
-* Running Guix Before It Is Installed:: Hacker tricks.
 
 Setting Up the Daemon
 
@@ -177,6 +178,21 @@ Packaging Guidelines
 * Perl Modules::                Little pearls.
 * Fonts::                       Fond of fonts.
 
+Contributing
+
+* Building from Git::           The latest and greatest.
+* Running Guix Before It Is Installed::  Hacker tricks.
+* The Perfect Setup::           The right tools.
+* Coding Style::                Hygiene of the contributor.
+* Submitting Patches::          Share your work.
+
+Coding Style
+
+* Programming Paradigm::        How to compose your elements.
+* Modules::                     Where to store your code?
+* Data Types and Pattern Matching::  Implementing data structures.
+* Formatting Code::             Writing conventions.
+
 @end detailmenu
 @end menu
 
@@ -253,7 +269,6 @@ instead, you want to install the complete GNU operating system,
 * Running the Test Suite::      Testing Guix.
 * Setting Up the Daemon::       Preparing the build daemon's environment.
 * Invoking guix-daemon::        Running the build daemon.
-* Running Guix Before It Is Installed::     Hacker tricks.
 @end menu
 
 @node Binary Installation
@@ -847,44 +862,6 @@ useful in exceptional circumstances, such as if you need to run several
 daemons on the same machine.
 @end table
 
-@node Running Guix Before It Is Installed
-@section Running Guix Before It Is Installed
-
-If you are hacking Guix itself---which is a good idea!---you will find
-it useful to test the changes made in your local source tree checkout
-without actually installing them.
-
-To that end, all the command-line tools can be used even if you have not
-run @command{make install}.  To do that, prefix each command with
-@command{./pre-inst-env} (the @file{pre-inst-env} script lives in the
-top build tree of Guix), as in:
-
-@example
-$ sudo ./pre-inst-env guix-daemon --build-users-group=guixbuild
-$ ./pre-inst-env guix build hello
-@end example
-
-@noindent
-Similarly, for a Guile session using the Guix modules:
-
-@example
-$ ./pre-inst-env guile -c '(use-modules (guix utils)) (pk (%current-system))'
-@end example
-
-The @command{pre-inst-env} script sets up all the environment variables
-necessary to support this, including @code{PATH} and
-@code{GUILE_LOAD_PATH}.
-
-If you are hacking Guix from Emacs using the wonderful Geiser
-(@pxref{Introduction,,, geiser, Geiser User Manual}), make sure to
-augment Guile's load path so that it finds source files from your
-checkout:
-
-@lisp
-;; Assuming the Guix checkout is in ~/src/guix.
-(add-to-list 'geiser-guile-load-path "~/src/guix")
-@end lisp
-
 
 @c *********************************************************************
 @node Package Management
@@ -6788,22 +6765,8 @@ Second, some of the required packages could fail to build for that
 platform.  Lastly, the generated binaries could be broken for some
 reason.
 
-
 @c *********************************************************************
-@node Contributing
-@chapter Contributing
-
-This project is a cooperative effort, and we need your help to make it
-grow!  Please get in touch with us on @email{guix-devel@@gnu.org} and
-@code{#guix} on the Freenode IRC network.  We welcome ideas, bug
-reports, patches, and anything that may be helpful to the project.  We
-particularly welcome help on packaging (@pxref{Packaging Guidelines}).
-
-Please see the
-@url{http://git.savannah.gnu.org/cgit/guix.git/tree/HACKING,
-@file{HACKING} file} that comes with the Guix source code for practical
-details about contributions.
-
+@include contributing.texi
 
 @c *********************************************************************
 @node Acknowledgments