vincent@pop-os:~$ sudo apt update && sudo apt upgrade
[sudo] password for vincent:
Ign:1 http://ppa.launchpad.net/materieller/teamspeak3/ubuntu disco InRelease
Ign:2 http://ppa.launchpad.net/mdeslaur/steamos/ubuntu disco InRelease
Ign:3 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:4 https://dl.winehq.org/wine-builds/ubuntu disco InRelease
Hit:5 http://ppa.launchpad.net/oguzhaninan/stacer/ubuntu disco InRelease
Hit:6 http://dl.google.com/linux/chrome/deb stable Release
Hit:7 http://ppa.launchpad.net/rael-gc/ubuntu-xboxdrv/ubuntu disco InRelease
Hit:8 http://ppa.launchpad.net/system76/pop/ubuntu disco InRelease
Hit:9 http://us.archive.ubuntu.com/ubuntu disco InRelease
Err:10 http://ppa.launchpad.net/materieller/teamspeak3/ubuntu disco Release
  404  Not Found [IP: 91.189.95.83 80]
Err:11 http://ppa.launchpad.net/mdeslaur/steamos/ubuntu disco Release
  404  Not Found [IP: 91.189.95.83 80]
Hit:12 http://apt.pop-os.org/proprietary disco InRelease
Hit:13 http://us.archive.ubuntu.com/ubuntu disco-security InRelease
Hit:15 http://us.archive.ubuntu.com/ubuntu disco-updates InRelease
Hit:16 http://us.archive.ubuntu.com/ubuntu disco-backports InRelease
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/materieller/teamspeak3/ubuntu disco Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'https://dl.winehq.org/wine-builds/ubuntu disco InRelease' doesn't support architecture '1386'
E: The repository 'http://ppa.launchpad.net/mdeslaur/steamos/ubuntu disco Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://ppa.launchpad.net/oguzhaninan/stacer/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://ppa.launchpad.net/rael-gc/ubuntu-xboxdrv/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://ppa.launchpad.net/system76/pop/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'restricted/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'multiverse/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'universe/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://apt.pop-os.org/proprietary disco InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-security InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'restricted/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-security InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'multiverse/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-security InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'universe/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-security InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-updates InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'restricted/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-updates InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'multiverse/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-updates InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'universe/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-updates InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'main/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-backports InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'restricted/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-backports InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'multiverse/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-backports InRelease' doesn't support architecture '1386'
N: Skipping acquire of configured file 'universe/binary-1386/Packages' as repository 'http://us.archive.ubuntu.com/ubuntu disco-backports InRelease' doesn't support architecture '1386'
vincent@pop-os:~$ sudo apt install pop-desktop
Reading package lists... Done
Building dependency tree
Reading state information... Done
pop-desktop is already the newest version (1.2.12~1556292703~19.04~b6b743d).
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
vincent@pop-os:~$ sudo apt install pop-desktop sessioninstaller
Reading package lists... Done
Building dependency tree
Reading state information... Done
sessioninstaller is already the newest version (0.20+bzr150-0ubuntu4.1).
sessioninstaller set to manually installed.
pop-desktop is already the newest version (1.2.12~1556292703~19.04~b6b743d).
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.