Starting g1
Starting g2
Finishing g2
Finishing g1
Traceback (most recent call last):
  File "test3.py", line 19, in <module>
    for x in g1():
  File "test3.py", line 8, in g1
    yield from g2()
  File "test3.py", line 15, in g2
    raise ValueError("spanish inquisition occurred")
ValueError: spanish inquisition occurred