Fix 'make html' build failures

Makefile

@@ -3,10 +3,10 @@
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
+SPHINXBUILD   = sphinx-build -v
 PAPER         =
 BUILDDIR      = build
-FILENAME      = $(shell cd source && python -c "from conf import basic_filename; print basic_filename")
+FILENAME      = $(shell cd source && python -c "from conf import basic_filename; print(basic_filename)")
 
 
 # Internal variables.

source/conf.py

@@ -22,7 +22,7 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.todo', 'sphinx.ext.ifconfig', 'sphinx_tabs.tabs', 'sphinxcontrib.jinja', 'sphinx-prompt']
+extensions = ['sphinx.ext.todo', 'sphinx.ext.ifconfig', 'sphinx_tabs.tabs', 'sphinx_jinja', 'sphinx-prompt']
 numfig = True
 
 # The suffix of source filenames.

source/riscv-sphinx/layout.html

@@ -37,7 +37,7 @@
 
   {% endif %}
 
-  <link rel="stylesheet" href="{{ pathto('_static/css/' + style, 1) }}" type="text/css" />
+  <link rel="stylesheet" href="{{ pathto('_static/css/theme.css', 1) }}" type="text/css" />
 
   {% for cssfile in css_files %}
     <link rel="stylesheet" href="{{ pathto(cssfile, 1) }}" type="text/css" />