D-Programming-Language/druntime — pull request #160 by CyberShadow (2012-02-24 05:02:58+00:00)
Title: Don't trap exceptions if a debugger is detected on Windows.

Having to "step into" the program every time you debug it to set `rt_trapExceptions` to false is a nuisance (perhaps more so with Windows debuggers than GDB). Fortunately, we can easily detect when our D program
is run under a debugger, and disable the default exception handler, so that an uncaught exception will be handled by the debugger.

I believe other Windows runtimes (C++/Delphi) do this as well.