How to fix: No module named apt_pkg This is what I get in my mail after cron-daily fails to upgrade: ⎗ ✓ 1 2 3 4 5 6 7/etc/cron.daily/apt: Traceback (most recent call last): File "/usr/bin/unattended-upgrade", line 55, in <module> import apt File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module> import apt_pkg ImportError: No module named 'apt_pkg' This can happen if you use python3.5 but have python-apt for 3.4. Here is how to fix this apt pkg thing: ⎗ ✓ 1 2 3 4 5apt-get install python3-apt --reinstall cd /usr/lib/python3/dist-packages ln -s apt_pkg.cpython-{34m,35m}-x86_64-linux-gnu.so ln -s apt_inst.cpython-{34m,35m}-x86_64-linux-gnu.so {34m,35m} - which link to which. If you use 3.6 but the module is 3.5 then do {3.5m,3.6m} etc