[plt-scheme] debugging [mini rant]

On Wed, 29 Jul 2009, Eli Barzilay might have said:

> On Jul 29, Mike Eggleston wrote:
> > 
> > Yes, much, and preferable in a production environment when you're
> > trying to figure out why something is not right. Any change you make
> > to the code must be tested again, so if you can run the code through
> > a debugger without changes is best. If you make a change to add
> > printf()s then you can't say for certain if your printf() caused the
> > error or if you've found the reported error.
> 
> This point is bogus.  I personally had one occasion where I had spent
> about 14 hours chasing a problem that we discovered in a release mode
> build of our product.  It was there for about a week before that (and
> it was the segfaulting kind of a problem), yet we didn't know about it
> because it didn't happen in debug mode.

Not bogus for me. I perform this type of debugging often on production
systems. I like to know I have made no changes to a system I'm trying
to find the error in, that I've not introduced another issue by changing
the code to add printf()s (stdout or file).

Mike