I'm Running Lilypond "Version 2.7.28-2 (Build from 30-12-2005 19:17"
[version string copied verbatim from "About Lilypond" window --
you might want to fix those parens, too] on OS X 10.4.4.
A double-quote instead of a single-quote in the wrong place, e.g.
(code)
\override NoteHead #'style = #"neomensural d\breve
%instead of
\override NoteHead #'style = #'neomensural d\breve
(end code)
can let some interesting sorts of hell break loose. In this case,
typesetting fails with the following error:
(log)
Parsing...ERROR: In procedure scm_lreadr:
ERROR: [path to file].ly:1:24: illegal character in escape sequence: #\b
(end log)
But that's not all. As soon as typesetting is done failing, OS X's
Crash Reporter pops up to tell me that Lilypond has "quit
unexpectedly", but Lilypond does not in fact quit; it keeps on running
normally. This is the only case I've seen of an app "crashing" without
actually ceasing to execute. As I write this, I've "crashed" Lilypond
a dozen times in a row without restarting it, and as soon as I fix the
incorrect quoting it typesets the file normally.
Here's the CrashReporter log entry.