Solving the issue where Flatpak applications cannot be updated.

At work, I’ve lost the ability to update Flatpak applications from the Flathub app store. The flatpak update command hangs on the message "Looking for updates…".

1) Determine which packages are installed at the system level and which are installed for the current user:

flatpak list --user
flatpak list --system

2) Try updating the packages with verbose error output.

If the packages are for the user, use the following command:

flatpak --user update -v

If the packages are for the system, use the following command:

sudo flatpak --system update -v

3) You can switch the Flatpak application source to a mirror in China. The address for the Chinese Flathub mirror is: https://mirror.sjtu.edu.cn/flathub. The command to switch to it is:

sudo flatpak remote-modify flathub --url=https://mirror.sjtu.edu.cn/flathub

4) Then run the update command for the user or for the entire operating system:

flatpak --user update -v
sudo flatpak --system update -v

5) Clean up unused Flatpak packages:

sudo flatpak uninstall --unused
flatpak --user uninstall --unused

List of Flathub Flatpak mirrors

Use one of the following commands to switch Flathub mirrors:

sudo flatpak remote-modify --no-follow-redirect flathub --url=https://front-ams.flathub.org/repo

sudo flatpak remote-modify --no-follow-redirect flathub --url=https://front-hex2.flathub.org/repo

sudo flatpak remote-modify --no-follow-redirect flathub --url=https://mirror.sjtu.edu.cn/flathub

wget https://mirrors.cernet.edu.cn/flathub/flathub.gpg
sudo flatpak remote-modify --gpg-import=flathub.gpg flathub --url=https://mirrors.cernet.edu.cn/flathub

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