2.7.4: sphinx errors about whoosh HOT 3 OPEN

+ /usr/bin/python3 setup.py build_sphinx -b man --build-dir build/sphinx
running build_sphinx
Running Sphinx v4.1.1
making output directory... done
loading intersphinx inventory from http://docs.python.org/objects.inv...
intersphinx inventory has moved: http://docs.python.org/objects.inv -> https://docs.python.org/3/objects.inv
building [mo]: targets for 0 po files that are out of date
building [man]: all manpages
updating environment: [new config] 58 added, 0 changed, 0 removed
reading sources... [100%] threads
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
writing... python-Whoosh.3 { releases/index releases/2_0 releases/1_0 releases/0_3 quickstart intro glossary schema indexing searching parsing querylang dates query analysis stemming ngrams facets highlight keywords spelling fieldcaches batch threads nested recipes api/api api/analysis api/codec/base api/collectors api/columns api/fields api/filedb/filestore api/filedb/filetables api/filedb/structfile api/formats api/highlight api/idsets api/index api/lang/morph_en api/lang/porter api/lang/wordnet api/matching api/qparser api/query api/reading api/scoring api/searching api/sorting api/spelling api/support/charset api/support/levenshtein api/util api/writing tech/index tech/backend tech/filedb } done
build succeeded.