Public bug reported: I started getting dark rectangles obscuring my main gnome-terminal windows when I left the session locked for a while. Description of chasing and removing these is at https://linux.codidact.com/posts/293718 , and the screenshot below shows some of those rectangles after I poked their size and opacity to better illustrate what happens.
Now I found the cause and a recipe to reproduce the bug. 1. Open a gnome-terminal (3.52.0-1ubuntu2) or xterm (390-1ubuntu3) window; but not foot (1.16.2-2ubuntu0.1) because it does not seem to be able to alert on terminal bell. For better confirmation: make the window a distinctive size, not full screen. 2. In gnome-control-center go to Accessibility > Hearing > Visual Alerts. Enable for "entire window". Bug seems not to trigger for "entire screen", but I didn't try hard because I don't want to dig myself out of that mess. 3. Run something that generates ASCII BEL for the remainder of the test such as `while true; do echo -ne \\a; sleep 1; done` . In my case it was the occasional bell of an email, a random factor which made it harder to figure out the cause. 4. Lock the screen. Bug does not trigger when screen is active. By rectangle counting, I suspect the bug also triggers during the password unlock dialog. 5. Expected: each visual alert to be finished and gone within a second of the BEL. 6. What you find when you unlock: a pile of semi-transparent dark rectangles stacked on your alerting window, approximately one per BEL emitted during the lock time. One or two might leave the text legible but dim, but more often the window is plain black. 7. Uf necessary, or you are curious about what they are: use the Wayland looking glass to find and delete the rectangles. https://linux.codidact.com/posts/293718 8. Switch Visual Alerts off and be grateful that you don't really need them. 🫣 Other notes that might be relevant: Grok advises that gnome-shell is the package providing this a11y function, so that's why I'm offering the report here. Grok also advises to give `journalctl /usr/bin/gnome-shell` output, but there is nothing recent ie. since last reboot. The opacity of these rectangles seems to vary, as if the visual alert were progressing as usual and then got an exception which prevented it becoming transparent and being deleted? It seems the visual alert was incomplete and not deleted. Mouse clicks can pass through them but the window's image is blocked or greatly darkened. The size of the rectangle seems to match the area flashed. This is more obvious after watching xterm flash repeatedly. With gnome-terminal it is possible to drag tabs out of the obscured window to "rescue" them... if you can see or guess where the tab is. --- Using a fairly standard Ubuntu 24.04.2 LTS Noble desktop on x86_64, $ lsb_release -rd No LSB modules are available. Description: Ubuntu 24.04.2 LTS Release: 24.04 $ apt-cache policy gnome-shell gnome-shell: Installed: 46.0-0ubuntu6~24.04.9 Candidate: 46.0-0ubuntu6~24.04.9 Version table: *** 46.0-0ubuntu6~24.04.9 500 500 http://archive.ubuntu.com/ubuntu noble-updates/main amd64 Packages 100 /var/lib/dpkg/status 46.0-0ubuntu6~24.04.3 500 500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages 46.0-0ubuntu5 500 500 http://archive.ubuntu.com/ubuntu noble/main amd64 Packages $ apt-cache policy xwayland xwayland: Installed: 2:23.2.6-1ubuntu0.5 Candidate: 2:23.2.6-1ubuntu0.5 Version table: *** 2:23.2.6-1ubuntu0.5 500 500 http://archive.ubuntu.com/ubuntu noble-updates/main amd64 Packages 100 /var/lib/dpkg/status 2:23.2.6-1ubuntu0.4 500 500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages 2:23.2.6-1 500 500 http://archive.ubuntu.com/ubuntu noble/main amd64 Packages --- So long and thanks for all the adjectival animals! ** Affects: gnome-shell (Ubuntu) Importance: Undecided Status: New ** Tags: a11y noble ** Attachment added: "Obscuring rectangles, after coords are modified through lg" https://bugs.launchpad.net/bugs/2113786/+attachment/5883060/+files/obscured.png -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/2113786 Title: Dark rectangle over gnome-terminal is a ghost of a "visual alert" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2113786/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
