Debugging/showing internal stuff?

[David Kastrup]

Hi, using a file debug.ly with the contents

#(top-repl)

I can get an interactive guile prompt.  However, things like
(display-scheme-music #{ \notemode { c' e'  g' c'' e'' } #})

which I picked off
<URL:http://nicolas.sceaux.free.fr/prelude/prelude.html> don't work.

I get

lilypond debug
GNU LilyPond 2.13.0
Processing `debug.ly'
Parsing...guile> 
(display-scheme-music #{ \notemode { c' e'  g' c'' e'' } #})
ERROR: In procedure ly:parser-clone:
ERROR: Wrong type argument in position 1 (expecting Lily_parser): #f
ABORT: (wrong-type-arg)
guile> 

What gives?  What should I rather write here?

-- 
David Kastrup