I'm tracking down the various "found repeated words in man page" errors in https://bugzilla.redhat.com/show_bug.cgi?id=1611292 but it's fiddly with such a large manpage.
It would be much easier if the test showed the location of the words within the decompressed manpage, ideally in gcc format:
FILENAME:LINE:COLUMN: MESSAGE
e.g.
foo.1:40:5: repeated word "bar"