pysais.lcp crashes python silently

I'm using python 3.6.6

Calling ```pysais.lcp(sequence, sa)``` is crashing silently- it seems to crash python entirely. Whether running a script that calls lcp or in interactive mode, it ends up closing python all together. The following code caused it on my end

```
import pysais
sequence = "aaabbbcccdddaaacccbbbddd"

sa = pysais.sais(sequence)
o = pysais.lcp(sequence, sa)
print(o)
```