dc (GNU 1.2) on Windows 10 x64, 185 bytes
dc doesn't crash fatally very often, and I couldn't be bothered to remember code that causes a segfault. I did recall some weird behavior involving arrays that causes a sad and total loss of the current session.
zzz zzzzzzz zz zzzzz zzzzz zzzzzzzzzz
zzzz zzzzzzzzzzz zzz zzzzzzzzz zzz zzzzzzz zz zzzzzzzzz zz zz zz zzzzzzz zzzz
zzzzzz zzzzzzz zzz zzzzzzzzzzzzz zzzzzzz zzzz zzz zzzz zzzzzzzz:zlz
Pushes numbers on the stack until the last five characters.
:z stores the second-to-topmost number in the topmost-indexed slot in the array named
z. Typically, this array would be linked through time and space to the current instance in the register named
z. However, we haven't actually put anything there. Next, we try to
lz, or copy the value on top of
z to the top of the main stack. We can't: there's nothing there. I'm not sure why this mechanism triggers the failure that it does, but it works. (Or...doesn't.) The trailing newline is significant for two reasons: it puts the code in the black at 185, and pasting it into
dc causes it to crash immediately.
Basically, we're running across a canyon, and as long as we don't look down, we're good. But once we look and realize we're floating in mid-air, we fall and crash hard, and little stars zoom around our poor befuddled heads.
Error, 184 bytes
dc: garbage in value being duplicated
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
I'm not sure if only part of that is the actual error or what, so feel free to correct me. The code is obviously very flexible when it comes to length.