Flatpak

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux.

error: While opening repository /var/lib/flatpak/repo: opening repo: opendir(/var/lib/flatpak/repo): No such file or directory

https://github.com/flatpak/flatpak/issues/5488#issuecomment-1697152286

error: No remote refs found for 'flathub'

❯ flatpak install flathub org.vinegarhq.Sober
Looking for matches…
error: No remote refs found for 'flathub'

Just run

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

error: Flatpak system operation EnsureRepo not allowed for user

If you get this after running command above, just append --user.

flatpak remote-add --if-not-exists --user flathub https://flathub.org/repo/flathub.flatpakrepo

bwrap: Can’t mount proc on /newroot/proc: Operation not permitted, error: ldconfig failed, exit status 256

bwrap: Can't mount proc on /newroot/proc: Operation not permitted
error: ldconfig failed, exit status 256

Just do incus config set <container name> security.nesting true.

Source