Sphinx to not assume python3 is the default python version

Adding in experimental makefile and sphinx script to explicitly
run using python3 instead of assuming the python command points
to a python3.x binary

2 files changed, 33 insertions, 0 deletions

diff --git a/doc/Makefile b/doc/Makefile
index d06c004fa..70e0ced95 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -14,6 +14,21 @@ ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) sou
 # the i18n builder cannot share the environment and doctrees with the others
 I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
 
+# Fix for when python is mapped to python2 not python3
+# This is an issue in the sphinx-build script provided in the default install
+# because it uses the generic python env, so we need to have a copy of this script
+# but with an explicit call to python3.
+#
+# Why python3? We are using some features of sphinx that are only implemented
+# currently in python3
+#
+PYV=$(shell python -c "import sys;t='{v[0]}'.format(v=list(sys.version_info[:2]));sys.stdout.write(t)")
+
+ifeq ($(PYV), 2)
+	SPHINXBUILD = ./sphinx-build3
+endif
+
+
 all: docs
 
 # Canned recipe for generating plugin api skeletons
@@ -65,3 +80,6 @@ docs: apidoc
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 
+testy:
+	@echo "Using $(SPHINXBUILD)"
+	@echo "Py is $(PYV)"
diff --git a/doc/sphinx-build3 b/doc/sphinx-build3
new file mode 100755
index 000000000..590fd5266
--- /dev/null
+++ b/doc/sphinx-build3
@@ -0,0 +1,15 @@
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+"""
+Same as /usr/bin/sphinx-build but with different
+interpreter
+"""
+
+import sys
+
+if __name__ == '__main__':
+    from sphinx import main, make_main
+    if sys.argv[1:2] == ['-M']:
+        sys.exit(make_main(sys.argv))
+    else:
+        sys.exit(main(sys.argv))
\ No newline at end of file