can error messages output the measure number being processed?

[Kieren MacMillan]

Hello all,

I'm working on a medium-sized score (chamber opera). I'm currently getting the 
following output:

Drawing 
systems.../Applications/Lilypond/LilyPond.app/Contents/Resources/share/lilypond/current/scm/bar-line.scm:926:28:
 In procedure ly:grob-array-length in expression (ly:grob-array-length 
bar-array):
/Applications/Lilypond/LilyPond.app/Contents/Resources/share/lilypond/current/scm/bar-line.scm:926:28:
 Wrong type argument in position 1 (expecting Grob_array): ()

1. I know the problem is in my own code (not bar-line.scm).
2. I even know with near certainty which of the 10 movements is causing the 
problem.
3. But it will still take a great deal of time to hunt down this problem in my 
code.
4. Lily-code debug time would be significantly decreased if errors outputted 
the measure number(s) being processed at the time the error occurred.

Is anything like this possible?
If so, how difficult is it to add this kind of logging to the codebase?

Thanks,
Kieren.