With current stable release 2.14.2 and development release 2.15.27
the processing time exceeds when several scores are typeset within
one book with given numer of systems per page.
Using 2.13.20 the attached sample works fine
(even a real life book with > 30 piano scores can be processed);
with 2.14.2 and later the file cannot be processed successful. (i didn't
check the versions prior to 2.14.2 yet)
When removing the line "systems-per-page = #7" the file can be processed.
The limit is reached with the 6th score block. With 5 scores the size of
each score can be increased up to more than 500 bars.
Using bookparts can be used to avoid this.
Maybe there've been some changes in the page breaking algorithm that
increases memory consumption ...
kind regards,
Martin