SQUASHME

Add a note to the docs that Python >= 3.6 is needed to generate the
Fortran docs.

Signed-off-by: Jeff Squyres <[email protected]>

Author: jsquyres

docs/developers/prerequisites.rst

@@ -47,6 +47,15 @@ build them manually, see the :ref:`how to build and install GNU
 Autotools section <developers-installing-autotools-label>` for much
 more detail.
 
+Python
+------
+
+Python >= v3.6 is required for generating the Fortran bindings, which
+is necessary if you build Open MPI from a Git clone.
+
+Python is also required for running Sphinx to generate the docs, too
+(:ref:`see below <developers-requirements-sphinx-label>`).
+
 Perl
 ----
 
@@ -88,6 +97,8 @@ MacPorts on MacOS), see `the Flex Github repository
 <https://github.com/westes/flex>`_.
 
 
+.. _developers-requirements-sphinx-label:
+
 Sphinx (and therefore Python)
 -----------------------------