Add a little note to "Building Python"

Author: encukou

Doc/using/configure.rst

@@ -4,6 +4,9 @@ Configure Python
 
 .. highlight:: sh
 
+
+.. _build-requirements:
+
 Build Requirements
 ==================
 
@@ -50,6 +53,8 @@ See also :pep:`7` "Style Guide for C Code" and :pep:`11` "CPython platform
 support".
 
 
+.. _optional-module-requirements:
+
 Requirements for Optional Modules
 ---------------------------------
 

Doc/using/unix.rst

@@ -84,11 +84,17 @@ On FreeBSD and OpenBSD
 Building Python
 ===============
 
+.. seealso::
+
+   If you want to contribute to CPython, refer to the
+   `devguide <https://devguide.python.org/getting-started/setup-building/>`_,
+   which includes build instructions and other tips on setting up environment.
+
 If you want to compile CPython yourself, first thing you should do is get the
 `source <https://www.python.org/downloads/source/>`_. You can download either the
-latest release's source or just grab a fresh `clone
-<https://devguide.python.org/setup/#get-the-source-code>`_.  (If you want
-to contribute patches, you will need a clone.)
+latest release's source or grab a fresh `clone
+<https://devguide.python.org/setup/#get-the-source-code>`_.
+You will also need to install :ref:`build requirements <build-requirements>`.
 
 The build process consists of the usual commands::