Fixes python#10020

Doc/library/sqlite3.rst

@@ -381,6 +381,8 @@ Connection Objects
 
    .. literalinclude:: ../includes/sqlite3/load_extension.py
 
+   Loadable extensions are disabled by default. See [#f1]_
+
 .. method:: Connection.load_extension(path)
 
    This routine loads a SQLite extension from a shared library. You have to
@@ -389,6 +391,8 @@ Connection Objects
 
    .. versionadded:: 3.2
 
+   Loadable extensions are disabled by default. See [#f1]_
+
 .. attribute:: Connection.row_factory
 
    You can change this attribute to a callable that accepts the cursor and the
@@ -880,3 +884,10 @@ threads. If you still try to do so, you will get an exception at runtime.
 The only exception is calling the :meth:`~Connection.interrupt` method, which
 only makes sense to call from a different thread.
 
+.. rubric:: Footnotes
+
+.. [#f1] The sqlite3 module is not built with loadable extension support by
+  default, because some platforms (notably Mac OS X) have SQLite libraries which
+  are compiled without this feature. To get loadable extension support, you must
+  modify setup.py and and remove the line that sets SQLITE_OMIT_LOAD_EXTENSION.
+