I'm reposting this as I didn't get an answer from my original posting. Surely someone here must know the answer!
I'm trying to find out exactly what grobs are produced as one point ins a score, so tried engraving with layout control and "display grob names" ticked on the layout control. And got this on the log:
warning: no such internal option: debug-grob-names
Processing `D:/Peter/Music/Lilypond/Herz/Variations/Intro/Intro.ly'
Parsing...C:/Program Files (x86)/Frescobaldi/frescobaldi_app/layoutcontrol/debug-layout-options.ly:65:8: In procedure ly:parser-include-string in _expression_ (ly:parser-include-string parser "\\include \"display-grob-names.ily\""):
C:/Program Files (x86)/Frescobaldi/frescobaldi_app/layoutcontrol/debug-layout-options.ly:65:8: Wrong number of arguments to #<primitive-procedure ly:parser-include-string>
Exited with return code 1.