Fix intersphinx mappings in documentation

python-sure.spec

@@ -37,6 +37,7 @@ BuildRequires:  python3dist(pytest)
 BuildRequires:  make
 BuildRequires:  python3dist(sphinx)
 BuildRequires:  python3dist(sphinx-rtd-theme)
+BuildRequires:  python3-docs
 
 %global common_description %{expand:
 An idiomatic testing library for python with powerful and flexible assertions
@@ -59,12 +60,24 @@ Summary:        %{summary}
 %package doc
 Summary:        Documentation for Sure
 
+Requires:       python3-docs
+
 %description doc %{common_description}
 
 
 %prep
 %autosetup -p1 -n %{srcname}-%{version}
 
+# Use local inventories in intersphinx mappings.
+#
+# Currently, python-redis does not package the Sphinx documentation, so we
+# remove that mapping:
+#   'redis': ('https://redis-py.readthedocs.io/en/latest/', None)
+sed -r -i \
+    -e 's|https://docs.python.org/3?|/%{_docdir}/python3-docs/html|' \
+    -e '/redis.*https.*readthedocs/d' \
+    docs/source/conf.py
+
 
 %build
 %pyproject_wheel