"man say" in macOS fails
I'm on High Sierra and when I do a man -aw say it shows the following:

$ man -aw say
/usr/share/man/man1/say.1


Which agrees with your location as well. You can use the following command to see how man is attempting to display the appropriate man page for say:

$ man -d say |&amp; grep say
  (cd '/usr/share/man' &amp;&amp; /usr/bin/tbl '/usr/share/man/man1/say.1' | /usr/bin/groff -Wall -mtty-char -Tascii -mandoc -c | (/usr/bin/less -is || true))


Based on that output my say.1 man page is located here: /usr/share/man/man1/say.1.

You can copy/paste this command in pieces to see where things are breaking for you as well.

For example:

$ cd '/usr/share/man'
$ /usr/bin/tbl '/usr/share/man/man1/say.1' | less
$ ...
$ ...


And keep adding pieces to see where it's failing on your end.