BUG: pytest with cProfile of test_numba segfault
```
python3 -m cProfile -o stats2.dat -m pytest pandas/tests/groupby/aggregate/test_numba.py
[...] 
collected 66 items                                                                                                                                                                                                                                                                  
pandas/tests/groupby/aggregate/test_numba.py ...Segmentation fault: 11
```

cc @mroeschke 