jit3_fail.py

import numba
import numba.types

src = '''
from __future__ import division
import numba.types

def f(x):
  j = numba.types.int32(0)
  return j+x
'''

print 'numba %s' % numba.__version__
glo = {}
loc = {}
exec(src, glo, loc)
f_python = loc['f']
f_native = numba.jit('i4(i4)')(f_python)

jit3_succeed.py

from __future__ import division
import numba.types

def f(x):
  j = numba.types.int32(0)
  return j+x

print numba.__version__
f_python = f
f_native = numba.jit('i4(i4)')(f_python)