Any way to peek at the exception currently being thrown?

[Elronnd]

On Friday, 4 June 2021 at 22:28:02 UTC, H. S. Teoh wrote:
> AFAIK, stack unwinding happens on the runtime stack, which is 
> TLS (because each thread by definition has its own stack).

Reminds me of a technique used by some early java VMs: they 
aligned all stacks to 2MB, so to get the 'thread id', all you had 
to do was check sp&-2MB.

(Much faster than a load through tls segment to a ptr probably 
not in cache.)