--- spack-src.org/umbrella/src/Makefile	2017-05-30 20:49:30.000000000 +0900
+++ spack-src/umbrella/src/Makefile	2019-11-20 17:23:42.101854924 +0900
@@ -16,7 +16,7 @@
 
 umbrella_helper.html: umbrella.py
 	# pydoc2/pydoc creates a html file, umbrella.html.
-	if which pydoc2; then pydoc2 -w umbrella; elif which pydoc; then pydoc -w umbrella; fi
+	if which pydoc; then pydoc -w umbrella; elif which pydoc2; then pydoc2 -w umbrella; fi
 	if [ -f umbrella.html ]; then mv umbrella.html umbrella_helper.html; fi
 
 clean: