When I enter the command:
sudo apt install libstdc++6:i386
I get the output:
The following packages have unmet dependencies: libstdc++6 : Breaks: libstdc++6:i386 (!= 8.2.0-1ubuntu2~18.04) but 8-20180414-1ubuntu2 is to be installed libstdc++6:i386 : Depends: gcc-8-base:i386 (= 8-20180414-1ubuntu2) but 8.2.0-1ubuntu2~18.04 is to be installed Breaks: libstdc++6 (!= 8-20180414-1ubuntu2) but 8.2.0-1ubuntu2~18.04 is to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
This answer (https://askubuntu.com/a/1104999/772004) shows that 8.2.0-1ubuntu2~18.04 refers to the "bionic-updates" repository, while 8-20180414-1ubuntu2 refers to the "bionic" repository.
Why are these packages in conflict? What does it mean that a different package is "to be installed"? Finally, how can I resolve the issue?
Edit: I did figure out a solution. I needed to add the bionic-updates and bionic-security repositories to my sources.list file. Also, Sophos AV was causing some trouble with apt. Once I changed sources.list and uninstalled Sophos AV, I was able to update and resolve all dependency issues.