So for some reason pyqtgraph started giving the segmentation fault immediately upon importing the module.
The strange thing was that after I installed it today for Python 3.52 and after installing all the other deps, it was working perfectly, including running examples for PyQt5.
The other strange thing is that it is working perfectly for Python 2.7 (with PyQt4).
...and I am having exactly the same problem but only in Python 3.52. I did the "gdb Python3" step and it reported the same string issue...
...
$ gdb python3
GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
Find the GDB manual and other documentation resources online at:
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from python3...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/bin/python3
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pyqtgraph
Program received signal SIGSEGV, Segmentation fault.
strlen () at ../sysdeps/x86_64/strlen.S:106
106 ../sysdeps/x86_64/strlen.S: No such file or directory.
(gdb)
...
I think the only thing I did between it working and giving a seg fault is that Mint update updated google Cloud SDK, but I cannot fathom what relationship that has except that I noticed it generated an error (did not note it).