Add more detailed information on prerequisites for building naclports.

README.rst

Index: README.rst
diff --git a/README.rst b/README.rst
index ec8da31287b66faca0147bb67ef098087946edd1..c3d300e99fd6727d730f5709a1d7b109f8bededc 100644
--- a/README.rst
+++ b/README.rst
@@ -17,6 +17,9 @@ a package into the toolchain run ``naclports.py install <package_dir>``.  This
 script will download, patch, build and install the application or library.  By
 default it will first build any dependencies that that the package has.
 
+Prerequistes
+------------
+
 The build scripts require that certain tools are present in the host system.
 You will need at least these:
 
@@ -35,6 +38,19 @@ To build all ports you will also need these:
 - autoconf, automake, libtool
 - libglib2.0-dev >= 2.26.0 (if you want to build glib)
 
+On Mac OS X you can use homebrew to install these using the following command::
+
+  brew install autoconf automake cmake gettext libtool pkg-config
+
+To the build system for some of the native python modules relies on a 32-bit

[binji, 2014/04/17 17:43:33]

s/To the build/The build/

[Sam Clegg, 2014/04/17 17:48:42]

Done.

+host build of the python itself, which in turn relies on the development version

[binji, 2014/04/17 17:43:33]

s/the python/Python/

[Sam Clegg, 2014/04/17 17:48:42]

Done.

+of zlib being available.  On 64-bit Ubuntu/Precise this means installing the
+following package: ``lib32z1-dev``.

[binji, 2014/04/17 17:43:33]

What about on Mac OS X?

[Sam Clegg, 2014/04/17 17:48:42]

Not sure at this point :(

+
+
+Building
+--------
+
 Before you can build any of the package you must set the NACL_SDK_ROOT
 environment variable to top directory of a version of the Native Client SDK
 (the directory containing toolchain/). This path should be absolute.
@@ -174,5 +190,4 @@ Whenever the upstream archive or patch file changes and you try to build the
 package you will be prompted to remove the existing repository and start a new
 one. This is to avoid deleting a repository that might have unsaved changed.
 
-
 Happy porting!