Recursive main() - why does it segfault?

Question

Why does the following program segfault?

int main() { main(); }

Even though it is a recursion that does not end and is therefore invalid by

Answer 1

Because every time it calls itself it allocates a little bit of stack space; eventually it runs out of stack space and segfaults. I'm a bit surprised it goes with a segfault, though; I would have expected (drum roll) stack overflow!