proper way to build [html]docs these days?

[Robert P. J. Day]

  just tried to build docs on a fully-updated fedora 31 system, and
got:

$ make htmldocs
  SPHINX  htmldocs --> file:///home/rpjday/uboot/git/doc/output
make[2]: Nothing to be done for 'html'.
Running Sphinx v2.1.2

Extension error:
Could not import extension kerneldoc (exception: cannot import name
'AutodocReporter' from 'sphinx.ext.autodoc' (unknown location))
make[1]: *** [doc/Makefile:68: htmldocs] Error 2
make: *** [Makefile:1984: htmldocs] Error 2
$

  i don't know enough about sphinx to know what to do with that
diagnostic -- what is the current way to build u-boot docs?

rday