A possibly silly question about debugging local customizations

Hi all,

I’m struggling to figure something out. When a modification is
dropped into the local tree and it causes breakage such that the mason
handler can’t even get going, how do I debug it? I don’t see it as
stderr going to Apache and it’s not going to syslog, either. Less
catastrophic errors seem to end up being dumped in their respective
components (i.e., if I screw up something with a Ticket/Elements
object, I’ll see it when I render a ticket and it’ll stop rendering
the ticket where it encounters the problem). This of course only
happens if I muck around with something really fundamental in lib/.
I’m sure there’s a simple pointer, but I’ve been googling about with
no success so far.