GDebi Package Installer not launching, and won't install .deb files on the ~/Desktop 18.10

Question

This morning I discovered that I can't launch GDebi. When I try to launch it from the SUPER menu, it puts its name in the top bar with a spinning cursor, stays there for about 10 seconds, and then disappears.

When I type sudo -H gdebi-gtk in the terminal, it launches fine.

Here's the desktop file...

[Desktop Entry]
Name=GDebi Package Installer
GenericName=Package Installer
Comment=Install and view software packages
Exec=sudo -H gdebi-gtk %f
Icon=gnome-mime-application-x-deb
Terminal=false
Type=Application
Categories=System;
MimeType=application/vnd.debian.binary-package;
NotShowIn=KDE;
X-Ubuntu-Gettext-Domain=gdebi
StartupNotify=true
Keywords=package;apt;dpkg;install

Here's some file info...

$ cd /usr/bin
$ ll gdebi*
lrwxrwxrwx 1 root root 20 Dec 31  2017 gdebi -> ../share/gdebi/gdebi*
lrwxrwxrwx 1 root root 24 Dec 31  2017 gdebi-gtk -> ../share/gdebi/gdebi-gtk*

$ ll /usr/share/gdebi
total 104K
drwxr-xr-x   3 root root 4.0K Jun 12 13:47 ./
drwxr-xr-x 527 root root  20K Oct 19 10:35 ../
-rwxr-xr-x   1 root root 4.0K Dec 31  2017 gdebi*
drwxr-xr-x   3 root root 4.0K Jun 12 14:04 GDebi/
-rwxr-xr-x   1 root root 3.5K Dec 31  2017 gdebi-gtk*
-rw-r--r--   1 root root 4.2K Feb 25  2010 gdebi.png
-rw-r--r--   1 root root  60K Jul  2  2015 gdebi.ui

Any idea why gdebi won't launch?

Answer 1

As far I can understand the installed /usr/share/applications/gdebi.desktop differs from your file:

$ cat /usr/share/applications/gdebi.desktop
[Desktop Entry]
Name=GDebi Package Installer
GenericName=Package Installer
Comment=Install and view software packages
Exec=gdebi-gtk %f
Icon=gnome-mime-application-x-deb
Terminal=false
Type=Application
Categories=System;
MimeType=application/vnd.debian.binary-package;
NotShowIn=KDE;
X-Ubuntu-Gettext-Domain=gdebi
StartupNotify=true
Keywords=package;apt;dpkg;install

It uses PolicyKit's pkexec to be ran as root:

$ dpkg -L gdebi | grep policy
/usr/share/polkit-1/actions/com.ubuntu.pkexec.gdebi-gtk.policy

So you should not use sudo for it.

I have just tested on my Ubuntu 18.10 VM - I can install manually downloaded deb-file:

apt-get download meld
gdebi-gtk meld*.deb

above I entered password and got Meld installed.

So consider to remove your self-made desktop file and reinstall the application with

sudo apt-get install --reinstall gdebi gdebi-core

---

Also you can try to reinstall PolicyKit-related components:

sudo apt-get install --reinstall policykit-1 python3-apt

---

I have checked your discovery about installation of deb-file from ~/Desktop folder.

And guess what?
I can confirm this issue on clean Ubuntu 18.10 installation. It is unbelievable.
I'm completely can not understand the modern GNOME philosophy.
But by the way I have reported bug 1807761 against nautilus-desktop executable (as it controls the desktop in 18.10) (and to upstream as bug 782) to help other users.

On upstream the bug is closed with comment:

António Fernandes commented:

Thanks for taking the time to report this.

Thay version of nautilus is no longer supported upstream, and nautilus-desktop is absent from the latest version (a shell extension is available as replacement).

So, a bug fix is not expectable from this side.

Conclusion: on modern GNOME you can't install deb-files from desktop. This will not be fixed in 18.10. And it is completely unpredictable what will be prohibited next time in 19.04.

Update: Ubuntu 18.04 LTS is affected too.

Answer 2

Go figure... reinstalling gdebi and gdebi-core fixed the launch problem. But the original problem remains.

Update #1:

So, now I recall... I previously had a problem where if gdebi is set as the default app for .deb files, when double-clicking on a .deb file, gdebi would open, and when I clicked on the Install Package button, where it should have asked for my user password, it just quit instead.

However, if I started gdebi first, and opened the .deb file manually, then clicked Install Package, it would properly ask for my user password, and would install the .deb file as expected.

My previous fix was to modify the .desktop file's Exec= line from:

Exec=gdebi-gtk %f

to

Exec=sudo -H gdebi-gtk %f

The reinstall undid that fix, cured the launch problem, but the user password and quit problem is back.

Update #2:

I reinstalled policykit-1 and python3-apt at the suggestion of @NOrbert. No joy.

Update #3:

Oh oh oh... fresh clue! The problem with gdebi-gtk occurs when trying to install a .deb file on my Desktop. However, if I move that same .deb into a fresh new folder on my Desktop, or into my Downloads folder, gdebi-gtk works fine!

@NOrbert has confirmed the problem.