Additional findings based on further log analysis: After reviewing the debug output more closely, it appears that Nautilus does attempt to generate thumbnails.
The log shows that thumbnail jobs are started and external thumbnailers are invoked (e.g. gdk-pixbuf-thumbnailer for images). However, these are executed via a bwrap (bubblewrap) sandbox, and this step fails with: bwrap: loopback: Failed RTM_NEWADDR: Operation not permitted Immediately afterwards, Nautilus reports: “Thumbnail failed … (The child process exited with status 1)” This suggests that the generic “subprocess failed with status 1” is only a follow-up error, and that the actual failure occurs earlier inside the sandboxed thumbnail generation. Manual tests confirm that the thumbnailers themselves work correctly when executed directly. Therefore, the issue does not appear to be caused by the thumbnailers themselves, but rather by the Nautilus / gnome-desktop thumbnailing pipeline when executed via bwrap. Additional note: One important observation is not directly visible in the debug log: As soon as Nautilus opens the folder, the “fail” directory is created immediately, including a 1x1 px black fail image. This happens right at startup, before any successful thumbnail generation is observed. Only a single 1x1 px fail image is created. No additional fail images are generated afterwards, regardless of how many files are present or which file types are tested. From that point on, all thumbnail attempts fail consistently, across all tested file types (images, MP3 embedded artwork, videos). This indicates that the initial fail-state acts as a persistent global block, rather than representing individual thumbnail failures. So while the log shows the sandboxed thumbnail process failing, the fail-state itself is already present from the very beginning and effectively blocks further attempts. Due to this behavior, further debugging from the user side is very limited, as it is only possible to observe the system in an already blocked state. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2148075 Title: Nautilus incorrectly marks thumbnails as failed although thumbnailers work correctly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/2148075/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
