To avoid duplication of work, I report my filing of the issue with gnome-desktop:
https://gitlab.gnome.org/GNOME/gnome-desktop/issues/4 I have a feeling bubblewrapping (i.e. bwrap), strict as it is configured at the moment, could potentially affect other packages generating thumbnails, e.g.: $ apt-file search /usr/share/thumbnailers | column -t -s : | sort atril-common /usr/share/thumbnailers/atril.thumbnailer blender-data /usr/share/thumbnailers/blender.thumbnailer dia-common /usr/share/thumbnailers/dia.thumbnailer evince /usr/share/thumbnailers/evince.thumbnailer exe-thumbnailer /usr/share/thumbnailers/exe-dll-msi.thumbnailer ffmpegthumbnailer /usr/share/thumbnailers/ffmpegthumbnailer.thumbnailer geogebra-gnome /usr/share/thumbnailers/geogebra.thumbnailer gnome-font-viewer /usr/share/thumbnailers/gnome-font-viewer.thumbnailer gnome-hwp-support /usr/share/thumbnailers/hwp-thumbnailer.thumbnailer gnome-nds-thumbnailer /usr/share/thumbnailers/gnome-nds-thumbnailer.thumbnailer gwyddion-common /usr/share/thumbnailers/gwyddion.thumbnailer heif-thumbnailer /usr/share/thumbnailers/heif.thumbnailer libgdk-pixbuf2.0-bin /usr/share/thumbnailers/gdk-pixbuf-thumbnailer.thumbnailer libgsf-bin /usr/share/thumbnailers/gsf-office.thumbnailer librsvg2-common /usr/share/thumbnailers/librsvg.thumbnailer mate-control-center-common /usr/share/thumbnailers/mate-font-viewer.thumbnailer mypaint /usr/share/thumbnailers/mypaint-ora.thumbnailer pentobi /usr/share/thumbnailers/pentobi.thumbnailer tiled /usr/share/thumbnailers/tiled.thumbnailer totem-common /usr/share/thumbnailers/totem.thumbnailer Do package maintainers run tests for thumbnailers? For example, we expect gnome-desktop to generate a thumbnail .png from the hash of the media resource as "URI-like" (not a full URI escaping, I have noticed, just some characters): (Python) hashlib.md5("file://" + sys.argv[1].replace(" ", "%20") .replace("|", "%7C")).hexdigest() do we verify that such file is created under: $XDG_CACHE_HOME/thumbnails/GNOME_DESKTOP_THUMBNAIL_SIZE_{NORMAL,LARGE} This would allow answering this type of questions programmatically: have changes in gnome-desktop broken the way in which the Blender thumbnailer works?
