[PATCH v3 2/2] ref-manual/system-requirements.rst: instruct to install a buildtools tarball

[Antonin Godard <antonin.godard@bootlin.com>]

I noticed that openSUSE Leap 15.6 provide Python 3.6, which is not
supported by BitBake (which requires Python >3.9). Instruct to use a
buildtools tarball, which is how this is done on the Autobuilder.

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
---
 documentation/ref-manual/system-requirements.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/documentation/ref-manual/system-requirements.rst b/documentation/ref-manual/system-requirements.rst
index dba11a135..05c852043 100644
--- a/documentation/ref-manual/system-requirements.rst
+++ b/documentation/ref-manual/system-requirements.rst
@@ -246,6 +246,11 @@ with a supported openSUSE Leap 15.6 distribution:
 .. literalinclude:: ../tools/host_packages_scripts/opensuse_essential_15.6.sh
    :language: shell
 
+Additionally, openSUSE Leap 15.6 requires a :term:`buildtools` tarball to be
+installed and set up, as this distribution provides a version of Python that is
+too old for :term:`BitBake`. Follow the :ref:`system-requirements-buildtools`
+section below for more information.
+
 Here are the packages needed to build Project documentation manuals:
 
 .. literalinclude:: ../tools/host_packages_scripts/opensuse_docs.sh

-- 
2.53.0