Write the shortest possible code cause an error due to recursion too deep

Example error in [python](/questions/tagged/python "show questions tagged 'python'")

```
RecursionError: maximum recursion depth exceeded

```

Example error in [c](/questions/tagged/c "show questions tagged 'c'")

```
Segmentation fault

```

My Python version (15 bytes):

```python
def f():f()
f()

```