Extra info from my Ubuntu MATE 18.04.5 LTS:
``` $ lsb_release -cs bionic
$ apt-cache policy sessioninstaller sessioninstaller: Installed: 0.20+bzr150-0ubuntu4.1 Candidate: 0.20+bzr150-0ubuntu4.1 Version table: *** 0.20+bzr150-0ubuntu4.1 500 500 http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages 500 http://archive.ubuntu.com/ubuntu bionic/universe i386 Packages 100 /var/lib/dpkg/status
$ apt-cache rdepends sessioninstaller sessioninstaller Reverse Depends: gnome-software gnome-software ubuntu-mate-desktop ubuntu-mate-core
$ aptitude why sessioninstaller i ubuntu-mate-desktop Recommends sessioninstaller ```
so the actual premise that nobody uses `sessioninstaller` was wrong.
Extra info from my Ubuntu MATE 18.04.5 LTS:
```
$ lsb_release -cs
bionic
$ apt-cache policy sessioninstaller 0ubuntu4. 1 0ubuntu4. 1 0ubuntu4. 1 500 archive. ubuntu. com/ubuntu bionic/universe amd64 Packages archive. ubuntu. com/ubuntu bionic/universe i386 Packages dpkg/status
sessioninstaller:
Installed: 0.20+bzr150-
Candidate: 0.20+bzr150-
Version table:
*** 0.20+bzr150-
500 http://
500 http://
100 /var/lib/
$ apt-cache rdepends sessioninstaller mate-desktop
sessioninstaller
Reverse Depends:
gnome-software
gnome-software
ubuntu-
ubuntu-mate-core
$ aptitude why sessioninstaller
i ubuntu-mate-desktop Recommends sessioninstaller
```
so the actual premise that nobody uses `sessioninstaller` was wrong.