RehearsalMark break-visibility

[Daniel Johnson]

I've been trying to get a rehearsal mark to show up at the end of a 
staff.  (The object is eventually to use markup such as a fermata 
here.)  Here's a stripped-down example:

%%%%% begin lilypond code %%%%%
\version "2.8.1"
eolMark = {
   \once\override RehearsalMark #'break-visibility = #end-of-line-visible
   \mark\default
   \break
}
\relative c' {
   c d e f g a b c \eolMark
   c b a g f e d c
}
%%%%% end lilypond code %%%%%

In this example, though, the rehearsal mark shows up at the beginning of 
the second line rather than the end of the first.  Any ideas?

--Daniel

P.S. Running version 2.8.1 on Linux