Why are breakpoints caught by the runtime?

[Daniel Murphy via Digitalmars-d]

"Trass3r"  wrote in message news:sgcekbmbxefmnghzsaaf at forum.dlang.org...

> Is there any good reason to catch that?
> I really want the debugger to fire up.

I know, I hate this.  You can disable it by changing rt_trapExceptions in 
dmain2.d in druntime to false and rebuilding druntime, which is horrible but 
what I usually do.  Unfortunately it is read before Dmain and the module 
constructors are run so it's tricky to clear on startup.