How to debug std::bad_alloc

[Jean-Charles Malahieude]

Hi all,

I've typeset BWV246 and printed an Urtext version without any problem.
A modern version spits me (version 2.17.20)

terminate called after throwing an instance of 'std::bad_alloc'
  what():  St9bad_alloc

I think I've narrowed the problem to a particular score which, when 
alone, compile fine.

I need some help in order to understand what's going wrong.

The only differences are:

- using \keepWithTag #'Full for modern
  as opposed to\keepWithTag #'(Full Urtext) for Urtext

- the global size

- some paper block variables
  inner-margin = 1.2\cm % for Urtext, 1cm
  outer-margin = 1.3\cm % for Urtext, 1cm
  binding-offset = 0.6\cm %for Urtext, 0.4cm
%  top-system-spacing #'basic-distance = #10 % for Urtext
%  top-markup-spacing #'basic-distance = #10 % for Urtext
%  last-bottom-spacing #'basic-distance = #10 % for Urtext

- nonstaff-unrelatedstaff-spacing
  minimum-distance at 2 in Urtext, 3 otherwise

- singers clefs

TIA,
JeanCharles