All documentation to the contrary, setting $MANPATH in my login file did not solve my problem of 'man' not being able to see the page posted by 'sudo make install'. But the 'man 7 man' output mentioned '/etc/manpath.config'. Adding a line
to this file did the trick. It made the documentation of all of the Perl modules that I've installed over the years, visible with 'man' as well as with 'perldoc'.
What Unix/Linux needs is not so much more drivers for trendy new devices, as reform/centralization of its sprawling mess of configuration files and diffuse technical details. Make new jobs by improving Unix/Linux infrastructure! Add this to the stimulus package! :-)