Build-Depends: s/python-sphinx/python3-sphinx/

debian/changelog

@@ -7,6 +7,7 @@ python-rdflib-jsonld (0.4.0-4) UNRELEASED; urgency=medium
   * Testsuite: autopkgtest-pkg-python
   * Secure URI in copyright format
   * Drop ancient X-Python-Version field
+  * Build-Depends: s/python-sphinx/python3-sphinx/
 
  -- Andreas Tille <tille@debian.org>  Tue, 30 Oct 2018 08:09:54 +0100
 

debian/control

@@ -13,7 +13,7 @@ Build-Depends: debhelper (>= 11~),
                python-html5lib,
                python-sparqlwrapper,
                python-nose,
-               python-sphinx,
+               python3-sphinx,
                python3-setuptools,
                python3,
                python3-all,