Getting Info to find extra pkgs not in normal path

[Harry Putnam]

I thought using a line like this:
 (add-to-list 'Info-default-directory-list 
   "/usr/local/src/stumpwm")

In ~/.emacs, would find any info files there when I call Info within
emacs.  Apparently that no longer works or maybe never worked.

There is an info file located there
ls /usr/local/src/stumpwm/*.info
/usr/local/src/stumpwm/stumpwm.info

But C-h i m stumpwm  knows nothing about it.