SUMMARY You can get into a situation where pressing [Esc] doesn't cancel a screenshot of a Rectangular Region. It seems to happen if you activate a KDE menu. STEPS TO REPRODUCE 1. Run a KDE app like KolourPaint 2. Run Spectacle, e.g. press [PrtSc] key. 3. Set Capture Mode to Area: Rectangular Region and Delay: 5 seconds 4. click [Take a New Screenshot] 5. Open a menu in KolourPaint, e.g. Help. Or right-click on any KWin titlebar. 6. Wait... 7. When Spectacle's prompt to "Click and drag to draw a selection rectangle, or press Esc to quit" appears, press [Esc] repeatedly. OBSERVED RESULT Pressing [Esc] doesn't cancel taking a screenshot. The cursor initially isn't Spectacle's '+' cursor, it's still a KDE menu cursor. Pressing [Esc] the first time changes the cursor to Spectacle's '+' cursor, but [Esc] still doesn't dismiss. The workaround is to left-click anywhere with the mouse to begin region selection (Spectacle's prompt changes), and now you can dismiss by pressing [Esc]. If you've already taken a rectangular region screenshot, the behavior is slightly different, but [Esc] still doesn't cancel. This bug *doesn't* happen if I open a Firefox menu (e.g. press [Alt+H] for help). EXPECTED RESULT Pressing [Esc] should always dismiss as the instructions say. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Plasma Version: 5.18.5 KDE Frameworks Version: 5.68.0 Qt Version: 5.13.2 running on xcb/X Windows. ADDITIONAL INFORMATION I'm sure this is a subtle interaction with X11 pointer and event grabbing :-) , but it confused me.
Yes that's X11 shenanigans. There's a workaround to grab the keyboard on first mouse click that's why it works after starting selection *** This bug has been marked as a duplicate of bug 407843 ***