Nightly GNOME Apps
Flatpak is a great way to safely install the latest development version of GNOME apps, alongside the regular stable versions. This is an easy way to test the next GNOME version.
Setting up GNOME nightlies
1. Install Flatpak and Flathub, following the standard instructions
2. Add the gnome-nightly repository, which provides the nightly GNOME runtime:
$ flatpak remote-add --if-not-exists gnome-nightly https://sdk.gnome.org/gnome-nightly.flatpakrepo
3. Add the gnome-apps-nightly repository, which provides the nightly GNOME apps:
$ flatpak remote-add --if-not-exists gnome-apps-nightly --from https://sdk.gnome.org/gnome-apps-nightly.flatpakrepo
Installing and running nightly apps
Once nightlies have been set up, they can be installed and run like any other Flatpak application. This includes installing them with Software or from the command line (see the Flatpak documentation for an overview of common commands).
Some useful commands for nightlies include:
List all the apps in the nightly repository: $ flatpak remote-ls gnome-apps-nightly
Install a nightly app: $ flatpak install gnome-apps-nightly org.gnome.App
Run a nightly version: $ flatpak run org.gnome.App//master
You can follow the build status of the applications in this website.