trying setjmp or throwing from signal handler crashes on OSX

[timotheecour]

> Since this is kind of low level I would guess you cannot just 
> take a Linux guide and have it work on Mac OS X. Both are Posix 
> but at this low level the differences between the platforms 
> start to show up.
>
> BTW, I get "Error: undefined identifier ucontext_t" when 
> compiling that file on Mac OS X.

I got that too. So I also tried linking my D program against a C 
library that would call those set jmp and long jmp functions, but 
that crashed too. So I guess there's currently no clean way to 
recover from signals on OSX ?