This is a tracking bug to switch gnome-software from the Ubuntu-specific apt backend to the PackageKit backend used by other distros. In particular this is the backend used by Debian.
To build, just uncomment the commented-out packagekit line in gnome-software's debian/rules and remove libapt-pkg-dev from Build-Depends. (You can also drop aptdaemon from Depends.)
Changes
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- It fixes some annoying bugs lingering in Ubuntu 16.04 LTS: LP: #1551599.
- It may also allow us to drop sessioninstaller (LP: #1661371)
- On an individual app page, Source is listed as something like 'ubuntu-zesty-universe' or ubuntu-yakkety-updates-main' or 'lp-ppa-gnome3-team-gnome3-staging-yakkety-main' instead of just 'Ubuntu'
- On an individual app page, apps from multiverse or restricted will show License as 'Proprietary' (example: VirtualBox or Devede ). This also happens for locally installed apps (i.e. not matching what's in your apt sources). I don't think it happens for PPAs since everything in a PPA is in 'main'.
- If you install an app using GNOME Software (or I assume another PackageKit app), it lists the date it was last installed or updated on the individual app page with a link to see its update history. (But the problem here is that update-manager doesn't use PK nor does apt on the command line.)
- Any update, no matter how small, is only permitted as an offline update. The button says "Restart & Install". It does seem to work fine though.
- Another bug is that installing or Removing an app inside GNOME Software is enough for it to "forget" about available Updates and think that everything is "up to date".
(It looks like gnome-software 3.24 will let us completely disable gnome-software's update mechanism and the Updates tab by default so these previous two differences may be irrelevant then.)
Sessioninstaller purely exists because of Aptdaemon - with Aptdaemon gone, native PackageKit frontends like GNOME Software and Apper can cover all of its functionality.
For the install- list-shorter issue, you might want to update to the current PackageKit release in unstable/testing, which contains a bugfix which might be related to this issue.