from numpy import *
import cPickle

a = zeros((300000, 1000)) 
f = open("test.pkl", "w") 
cPickle.dump(a, f)

------
SystemError: Traceback (most recent call last)

/home/kddcup/code/matt/svd-projection/take5/<ipython console> in <module>()

SystemError?: error return without exception set

Or using the .dump function:

a.dump("test.pkl")

SystemError? Traceback (most recent call last)

/home/kddcup/code/matt/svd-projection/take5/<ipython console> in <module>()

SystemError: NULL result without error in PyObject?_Call

I am not sure if this is a numpy or Pickle/cPickle glitch. In either case, even if this is a semi-known behavior, a more instructive error message would certainly help. I think the problem only happens for arrays larger than 2**(32-1) bytes but I would have to experiment more to be sure.

See also issue11564 and issue9614.

It is an integer overflow issue. It is easy to reproduce without numpy:

$ python2.7 -c "import cPickle; cPickle.dumps('\x00' * 2**31)"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
SystemError: error return without exception set

We fixed this in Python 3. It may be worthwhile to fix cPickle as well.

Is this issue still actual?