When the directory is bad, we need to send a list of path-labels; the
original code would pass in a path object and would emit a contract
error of the form:
dyoo@kfisler-ra1:~$ set in list-box%: expected argument of type <list of strings (up to 200 characters)>; given ("Bad Directory:" #<path:/home/dyoo/tmp/>)
svn: r9868