No longer changing warnings into errors for the target html
Index: sympy/doc/Makefile
===================================================================
--- sympy.orig/doc/Makefile
+++ sympy/doc/Makefile
@@ -1,6 +1,6 @@
 # Makefile for Sphinx documentation
 #
-PYTHON       = python
+PYTHON       = python3
 RST2HTML     = rst2html
 
 # You can set these variables from the command line.
@@ -71,7 +71,9 @@ _html: $(BUILDDIR)/logo/sympy-notailtext
 printwarnings:
 	@printf "\033[0;31mThe docs build failed with the following errors:\033[0m\n"
 	@cat $(WARNINGSFILE)
-	exit 1
+	# ignore warnings, for a debian package build
+	# exit 1
+
 
 $(BUILDDIR)/html/pics/*.png: $(SOURCEDIR)/pics/*.png
 	mkdir -p $(BUILDDIR)/html