It can't be. It is not POSIX-compliant, not portable and can potentially corrupt your application on some systems. This is why it was rejected as an official part of standard library and is being kept as extra hidden module.
But null pointer exception is very common mistake even for Dlang, and current reaction (silent core dump) is so bad for real life :(
I think, Vibe.d should handle it in some way before getting production ready status.