For anyone finding this thread because they searched for the libc6-dev, libgcc-8-dev, gsettings-desktop-schemas, mutter, upgrade errors: the solution can be found here Upgrade to Byzantium
For anyone finding this thread because they searched for the libc6-dev, libgcc-8-dev, gsettings-desktop-schemas, mutter, upgrade errors: the solution can be found here Upgrade to Byzantium