Bug#1029643: Caja doesn't show previews ('thumbnails') for pictures
Package: caja
Version: 1.24.0-1
Severity: normal
Tags: patch
Dear maintainers
After upgrading Debian GNU/Linux from Buster to Bullseye by following
the procedure that is detailed in the Release Notes, after carefully
removing the remaining packages that belonged to Buster, and after
installing the package usrmerge to transform my file system to the
modern form, it appeared that the file manager Caja of my MATE desktop
environment did not show previews ('thumbnails') of pictures any more.
To investigate and eventually solve the problem, I took the following steps.
- The settings of Caja were checked. There was nothing wrong. In the
Preview tab of the Preferences, miniature pictures are to be shown for
local files that are smaller than 5 MB.
- The packages that directly relate to Caja were reinstalled with
Synaptic, because the problem might have been caused by usrmerge. The
following packages were reinstalled: caja (1.24.0-1), caja-common
(1.24.0-1), caja-extensions-common (1.24.1-1), libcaja-extension1
(1.24.0-1). However, that didn't help.
- After Internet research of the problem, the access rights of
~/.cache/thumbnails were checked and the folder ~/.cache/thumbnails was
even removed. However, that also didn't help.
- The package pcmanfm was installed. PCManFM is another file manager. It
performed better, but it fell short of showing every JPG-file with a
preview.
- The package caja was completely removed (including its
configuration). In order to do this, the packages mate-desktop,
mate-desktop-environment-core and task-mate-desktop had to be removed
too. Immediately after removal, task-mate-desktop was installed again,
to install all four packages again. This also didn't help.
- The package gir1.2-caja-2.0 was installed for a try, but it didn't
help, and then it was removed.
- The system log was monitored. Caja was used to open a folder with
pictures to create the problem. However, Caja did not report anything to
the system log.
- More Internet research was carried out. Someone had a similar problem
with Thunar, another file manager. Thunar uses tumbler, which I do not
have installed. Synaptic reports that tumbler is a dependency of thunar
but not of caja.
- The folder /usr/share/thumbnailers was mentioned on the Internet. This
folder was found to exist on my system. It contained the file
ffmpegthumbnailer.thumbnailer and three others. By examining them, it
was found that ffmpegthumbnailer.thumbnailer deals with video files
only, and that there was not a file that deals with JPG files.
- Someone on an internet forum asked someone else whether
libgdk-pixbuf2.0-bin is installed. This package was not installed on my
system and Synaptic says in the description that it is a thumbnailer.
- I noticed that libgdk-pixbuf2.0-bin is a bad name for a thumbnailer. I
also noticed that there are four packages installed which names begin
with libgdk: libgdk-pixbuf-2.0-0, libgdk-pixbuf-xlib-2.0-0,
libgdk-pixbuf2.0-0 and libgdk-pixbuf2.0-common. The second,
libgdk-pixbuf-xlib-2.0-0 is a 'GDK Pixbuf library (deprecated Xlib
integration)'. It is deprecated, but it couldn't be removed because many
important packages depend on it. Thus, Debian seemed to have made a mess
around here.
- After libgdk-pixbuf2.0-bin was installed, both Caja and PCManFM worked
perfectly. Installing libgdk-pixbuf2.0-bin also resulted in
/usr/share/thumbnailers having a fifth file
gdk-pixbuf-thumbnailer.thumbnailer, which deals with JPG files indeed.
Solving the problem took me three days. However, Synaptic did not report
any defective packages after the upgrade to Bullseye. Furthermore, if
Caja has preferences that can be set to show previews, then setting them
to show previews should simply take effect.
CONCLUSIONS
Caja doesn't show previews ('thumbnails') of pictures if
libgdk-pixbuf2.0-bin is not installed.
It appears that libgdk-pixbuf2.0-bin is not a dependency of caja,
although it should have been.
It appears that libgdk-pixbuf2.0-bin is also not a recommended package
for caja, leaving the troubled user without a clue.
REMARKS
The package nautilus only recommends libgdk-pixbuf2.0-bin. That is not
correct in my opinion. If a file manager doesn't warn on the appropriate
preference GUI about a missing package, then whatever someone chooses
should simply work.
Only when this bug report was proofread for a second time, it was found
that libgdk-pixbuf-2.0-0 recommends libgdk-pixbuf2.0-bin. This shows
once more how difficult it has been made to solve this problem.
Kind regards
Maarten
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