Environment

• linux 5.4.13
• python 3.9.0b3
• ipython 7.19.0
• matplotlib 3.3.3
• texlive 2019-r1 (maybe useful)
• qt 5.15.0 (maybe useful)
• jupter 1.0.0-r2 (but i use ipython in terminal not jupyter)

Reproduce Procedures

%matplotlib qt
import matplotlib.pyplot as plt
fig,ax=plt.subplots(1,1)
ax.set_xlabel('测试',fontdict={'family': 'WenQuanYi Micro Hei'})
plt.savefig('a.pdf')

[1]    50554 segmentation fault (core dumped)  ipython

Note

WenQuanYi Micro Hei is a open source chinese font and can be installed by
sudo emerge -av media-fonts/wqy-microhei in my distribution. replacing it
with any Chinese font will result in the same bug. if replace it with any
non-Chinese font will not output Chinese character and avoid the bug.

if the picture format is png, the bug will not occur, and the file a.png
will be normal.