Special setup for Guix atop another distro

[Ludovic Courtès]

Hello!

Our manual lacks info on things that need to be tweaked when using Guix
on top of another distro.

To get the discussion started, here’s a preliminary patch for you people
to complete.  :-)

Please report all the things that you’ve had to tweak, or annoyances
that you don’t know how to fix.

Ludo’.

diff --git a/doc/guix.texi b/doc/guix.texi
index 6964a4e..056518f 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -87,6 +87,7 @@ Installation
 * Running the Test Suite::      Testing Guix.
 * Setting Up the Daemon::       Preparing the build daemon's environment.
 * Invoking guix-daemon::        Running the build daemon.
+* Application Setup::           Application-specific setup.
 
 Setting Up the Daemon
 
@@ -246,6 +247,7 @@ 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.
+* Application Setup::           Application-specific setup.
 @end menu
 
 @node Binary Installation
@@ -830,6 +832,39 @@ daemons on the same machine.
 @end table
 
 
address@hidden Application Setup
address@hidden Application Setup
+
+When using Guix on top of another GNU/Linux distribution, you may find
+that a few additional steps are needed to get everything in place.  Here
+are some of them.
+
address@hidden Locales
+
+Packages installed @i{via} Guix will not use the host system's locale
+data.  Instead, you must first install one of the locale packages
+available with Guix and the define the @code{LOCPATH} environment
+variable (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library
+Reference Manual}):
+
address@hidden
+$ guix package -i glibc-locales
+$ export LOCPATH=$HOME/.guix-profile/lib/locale
address@hidden example
+
+FIXME: Anything else?
+
address@hidden X11 Fonts
+
+The majority of graphical applications uses Fontconfig to locate and
+load font and perform X11-client-side rendering.  Guix's
address@hidden package looks for fonts in the user's profile by
+default, so you have to install them there.
+
+FIXME: but actually Fontconfig's cache will have the host distro's fonts
+listed, so maybe this is not a problem?
+
+
 @c *********************************************************************
 @node Package Management
 @chapter Package Management