https://bugs.gentoo.org/716774

--- a/build/sphinx/taglist.py
+++ b/build/sphinx/taglist.py
@@ -24,7 +24,12 @@ THE SOFTWARE.
 """
 
 from docutils import nodes, utils
-from sphinx.environment import NoUri
+
+try:
+    from sphinx.environment import NoUri
+except ImportError:
+    from sphinx.errors import NoUri
+
 try:
     from sphinx.util.compat import Directive
 except ImportError: