Use the local python binary to build the docs, not whatever 'python' is on the PATH (which is probably Python 2.x, and we need 3.x).

Author: collinw

Doc/Makefile

@@ -73,7 +73,7 @@ TOOLSDIR=	tools
 # commontex/patchlevel.tex in their dependencies.
 RELEASE=$(shell $(PYTHON) tools/getversioninfo)
 
-PYTHON=	   python
+PYTHON=	   $(PWD)/../python
 DVIPS=	   dvips -N0 -t $(PAPER)
 
 # This is ugly!  The issue here is that there are two different levels