# Kernel dies when working with hyperplane arrangement

Following function causes kernel restart on any usage of "ha" (Sage 7.4, VirtualBox in Windows7 x64):

```
def f(n):
pos_vectors = [[1, 1, 1, 1], [1, -1, 1, 1], [1, 1, -1, 1], [1, -1, -1, 1], [1, 1, 1, -1], [1, -1, 1, -1], [1, 1, -1, -1], [1, -1, -1, -1]]
HA = HyperplaneArrangements(QQ, tuple("x" + str(i) for i in range(n)))
ha = HA([[tuple(vector), 0] for vector in pos_vectors])
print(ha.n_regions())
f(4)
```

Too simple use case for bug. Is there something that I miss?

I can't reproduce this (Sage 7.4beta, on Mac). Did you do anything else before this? It went pretty fast, too, less than 100 ms.

No, only this function. I made mistake, version of Sage is 7.4