Unable to install deb-file stored on Desktop (which is controlled by nautilus-desktop) with GDebi

[Norbert]

Steps to reproduce:
1. Install Ubuntu 18.04 LTS or Ubuntu 18.10
2. Download some deb-file to the desktop - for with help of terminal:

     cd ~/Desktop
     apt-get download meld

3. Install GDebi package installer with

     sudo apt install gdebi

4. Select deb-file on desktop, make right click on it, select *Open With Other Application* select *GDebi Package Installer*, click *Select*, in opened window select *Install Package*

Expected results:
* GDebi asks user (sudo-able) password and installs the package

Actual results:
* GDebi do not ask user for password and do not install the package

Notes:
* first seen on AskUbuntu ( https://askubuntu.com/q/1099387/66509 )
* you can view my screencast to get first person view :)

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: nautilus 1:3.26.4-0ubuntu7
ProcVersionSignature: Ubuntu 4.18.0-12.13-generic 4.18.17
Uname: Linux 4.18.0-12-generic x86_64
ApportVersion: 2.20.10-0ubuntu13.1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Dec 10 23:14:16 2018
GsettingsChanges:

SourcePackage: nautilus
UpgradeStatus: No upgrade log present (probably fresh install)
usr_lib_nautilus:

[Norbert (nrbrtx)]

Reported to upstream as https://gitlab.gnome.org/GNOME/nautilus/issues/782 .

[Sebastien Bacher (seb128)]

is the issue only happening on the desktop view? does it work in 'normal' directories?

[Norbert (nrbrtx)]

This happens only on desktop. Which is controlled by `nautilus-desktop` executable (part of `nautilus` package).

So I think that GDebi is not really affected.
I assume that pkexec-ed applications are not runnable from `nautilus-desktop`.

[Norbert (nrbrtx)]

And Ubuntu 18.04 LTS (xenial) is affected too.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sebastien Bacher (seb128)]

Could you look in the list of process what url was called exactly for gdebi? maybe it's using a x-desktop: url which gdebu doesn't handle?

[Norbert (nrbrtx)]

Thanks for idea, but on launch gdebi is shown in `htop` as

   /usr/bin/python3 /usr/bin/gdebi-gtk /home/user/Desktop/meld_3.18.0-6_all.deb

then it closes after clicking on *Install package* button. I do not know how to debug this deeper.

[Doug McMahon (mc3man)]

It would appear the issue is that a gdebi instance opened from the context menu on a desktop item is unable to do any action on any .deb file located anywhere. In other words it's doomed to fail upon simply opening.

Can be easily seen by opening gdebi-gtk as described but then switching to another .deb somewhere else from gdebi's open menu item. This will also fail.

gdebi-gtk opened from app menu has no issues acting on a .deb from anywhere inc. the desktop

[Sebastien Bacher (seb128)]

That's still an issue in disco/with gnome-shell-extension-desktop-icons