import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import torch

fig = plt.figure()
plt.plot([1,2])
fig.savefig('test.pdf')

Running this simple python code will have error *** Error in 'python': free(): invalid pointer: 0x00007f5ba8129ac0 *** (omit the backtrace output). It breaks at fig.savefig('test.pdf').

OS Ubuntu 16.04.2 LTS, Python version 2.7.12, PyTorch version 0.1.12_2, Matplotlib version 2.0.2