Error during import

[DumbMachine]

If cv2 python package is imported after importing ngtpy, it results to a free(): invalid pointer. Below is a example:

(base) ➜  search_test git:(master) ✗ ipython                 
Python 3.7.4 (default, Aug 13 2019, 20:35:49) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import ngtpy 
   ...: import cv2 
   ...:                                                                 
free(): invalid pointer
[1]    703 abort (core dumped)  ipython

But importing cv2 before would'nt result to this issue.

(base) ➜  search_test git:(master) ✗ ipython
Python 3.7.4 (default, Aug 13 2019, 20:35:49) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import cv2 
   ...: import ngtpy 
   ...:                                                                 

In [2]:     

[masajiro]

For ubuntu, when you install opencv with pip, this problem occurs. However when you install opencv with apt, it doesn't.