I installed Python 3.6 from J Fernyhough's PPA by doing

sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install python3.6

I made a string, using the new literal string interpolation, but I supplied an invalid format specifier. I not only got the expected "ValueError: Invalid format specifier", but also the unexpected "ModuleNotFoundError: No module named 'apt_pkg'".


$ python3.6
Python 3.6.0 (default, Dec 29 2016, 21:40:36) 
[GCC 5.4.1 20161202] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> value = 4 * 20
>>> f'the value is {value:%A}'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: Invalid format specifier
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
    from apport.report import Report
  File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
    import apport.fileutils
  File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
    from apport.packaging_impl import impl as packaging
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>
    import apt
  File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
    import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'

Original exception was:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: Invalid format specifier