CGAL + GMP

If you use CGAL with GMP for numerics, you might want to compile a debug version of GMP. The problem is: GMP will abort if it gets bogus input (like a NaN floating point initializer).  But GMP is normally coded with stack back-links disabled for speed.  This means that if you have a NaN in your code, as soon as CGAL passes it to GMP you get a crash with no back-trace to see how it happened.

The fix is to recompile GMP in some kind of debug mode for development purposes.