I'm using Ubuntu 16.04.
When I update, I got the following message
$ sudo apt-get update
....
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
Following the error message, I try
$ sudo dpkg --configure -a
setting up snapd (2.14.2~16.04) ...
then it hangs forever. Does anybody know how can I fix this problem? Thanks.