Comment 0 for bug 2052851

On Ubuntu 23.10...

* When adding a PPA, 'add-apt-repository' will add the repository in the new deb822 format as a <ppa-name>.sources file in '/etc/apt/sources.list.d'

* However, 'add-apt-repository --list' cannot see/understand the new '<ppa-name>.sources' file

For example, with the flacon ppa (https://launchpad.net/~flacon/+archive/ubuntu/ppa):

1. `sudo add-apt-repository ppa:flacon/ppa` adds the flacon repo as `/etc/apt/sources.list.d/flacon-ubuntu-ppa-mantic.sources`

2. apt can install and update from the new repo, as expected. you can also remove the repo, as expected, by running `sudo add-apt-repository --remove ppa:flacon/ppa`

3. However, `add-apt-repository --list` does not list the repo as it should. GUI package managers such as Muon and Synaptic also do not see the new repo.

It makes working with packages quite frustrating, and unfortunately, per Julian Andres Klode (juliank), there seems to be no plan to fix the broken `software-properties-common`. See here:

https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/2033949

Also see related issues:

https://bugs.launchpad.net/ubuntu/+source/ppa-purge/+bug/2036761
https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/2037210
https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2036288
https://lists.ubuntu.com/archives/ubuntu-devel/2023-September/042791.html