> Regarding the stack trace, I don't like the idea of having it only in debug mode...

After battling with huge stack traces, there's another related feature that I'd like to have on default: stack trace compression. If a recursive function keeps calling itself, or two functions keep calling each other (other possibilities exist, but those two cover most cases), the stack trace can become too much long to print and read.

So just looking at the latest stack frame printed and penultimate stack frame printed it can compress it, reporting only how many time the last one or the last two ones are repeated (the uncompressed stack trace can be obtained on request, that shows all the line numbers too).

Bye,
bearophile