sphinx woes

[Greg Troxel <gdt%lexort.com@localhost>]

netbsd-8, amd64, up-to-date pkgsrc, the following installed packages
cannot be built:

  py37-sphinxcontrib-serializinghtml py37-sphinxcontrib-htmlhelp py37-sphinxcontrib-devhelp

and it all seems to be about PLIST and translations.
Between check-in PLIST and print-PLIST,  I see

@@ -92,8 +92,7 @@
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/sphinxcontrib.devhelp.pot
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/sr/LC_MESSAGES/sphinxcontrib.devhelp.mo
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/sr/LC_MESSAGES/sphinxcontrib.devhelp.po
-${PYSITELIB}/sphinxcontrib/devhelp/locales/sr@latin/LC_MESSAGES/sphinxcontrib.devhelp.mo
-${PYSITELIB}/sphinxcontrib/devhelp/locales/sr@latin/LC_MESSAGES/sphinxcontrib.devhelp.po
+${PYSITELIB}/sphinxcontrib/devhelp/locales/sr@latin/LC_MESSAGES/sphinxcontrib.devhelp
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/sv/LC_MESSAGES/sphinxcontrib.devhelp.mo
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/sv/LC_MESSAGES/sphinxcontrib.devhelp.po
 ${PYSITELIB}/sphinxcontrib/devhelp/locales/ta/LC_MESSAGES/sphinxcontrib.devhelp.mo