Meld: comparison panes are left blank with lot of error messages about missed icons in Adwaita theme

[Maxime]

I have tried to compare two directories using Meld. Unfortunately it left comparison panes empty blank, though color markups on the scrollbars of these panes indicate presence of changes.

Meld writes to stderr a lot of messages like the following about missing icons in the Adwaita theme:

gi.repository.GLib.Error: gtk-icon-theme-error-quark: Icon 'text-x-generic' not present in theme Adwaita (0)
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/meld/ui/emblemcellrenderer.py", line 95, in do_render
    pixbuf = self._get_pixbuf(self._icon_name, self._icon_size)
  File "/usr/lib/python3/dist-packages/meld/ui/emblemcellrenderer.py", line 83, in _get_pixbuf
    pixbuf = icon_theme.load_icon(name, size, 0).copy()

gi.repository.GLib.Error: gtk-icon-theme-error-quark: Icon 'folder' not present in theme Adwaita (0)
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/meld/ui/emblemcellrenderer.py", line 95, in do_render
    pixbuf = self._get_pixbuf(self._icon_name, self._icon_size)
  File "/usr/lib/python3/dist-packages/meld/ui/emblemcellrenderer.py", line 83, in _get_pixbuf
    pixbuf = icon_theme.load_icon(name, size, 0).copy()

It is expected the meld would show differences on both panes.

Workaround: install adwaita-icon-theme-full package. After installation the meld works as expected.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: meld 3.20.2-1ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Tue May 5 13:06:54 2020
InstallationDate: Installed on 2020-04-09 (25 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200408)
PackageArchitecture: all
SourcePackage: meld
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Alistair Turnbull (apt1002)]

I managed to fix this with `apt install adwaita-icon-theme-full`. It looks to me like a missing dependency in the "meld" package.

[bill (kapaki)]

I can confirm that `apt install adwaita-icon-theme-full` fixed this for me too. (Ubuntu 20.04)

[Hans Deragon (deragon)]

Same problem with Ubuntu 22.04 LTS (Jammy Jellyfish), and the same solution applies, i.e. `apt install adwaita-icon-theme-full`.

Can someone ask the packager to simply add this dependency? I do not know how to make contact. With `sudo apt show meld` I do find:

Maintainer: Ubuntu Developers <email address hidden>
Original-Maintainer: Debian GNOME Maintainers <email address hidden>

...but I am not sure.