The Ubuntu packaging is maintained at
https://code.launchpad.net/~ubuntu-desktop/gnome-software/ubuntu

Patches are maintained at https://gitlab.gnome.org/ubuntu/gnome-software
in ubuntu-* branches. These branches are regularly rebased.

To inspect these changes individually, please issue

  $ git clone -b ubuntu-3-26 https://gitlab.gnome.org/ubuntu/gnome-software.git
