Most users of Debian-based distributions are familiar with the single line apt repository format which includes all of the information for a repository. With the new DEB822 format, those single lines are converted to multi-line entries, which allow more flexibility and extensibility over the standard for Debian software repositories.
In fact, the single-line format standard is planned for depreciation, so most distributions will eventually convert over. For Pop!_OS users, that time is now. Pop!_OS is the Linux distribution created by System 76 as both a developer and general usage desktop operating system. Up until 20.10, Pop!_OS defaulted to the single-line style of repository entries. Now, instead of the /etc/apt/sources.list file, you’ll find those repository entries in /etc/apt/sources.list.d/system.sources. As well, instead of a number of entries, (at least as of the initial release) you’ll find only one in that file, which follows the new DEB822 format of:
- URIs: - repository address
- Suites: various release-related repositories (such as groovy groovy-security groovy-updates groovy-backports)
- Components: main and other resotories (such as universe and multiverse)
The idea behind DEB822 is that it should make it easier for users, developers, and even machines to create, extend and modify apt entries, especially if a larger number of sources and/or options are involved.
Although not all repositories work with the new format yet, developers are being encouraged to switch to the new multi-line style.