Package: xfce4-screenshooter
Version: 1.10.5-1
Running xfce desktop for a long while, by guessing, 1day or longer, with or without suspend/wakeup.
Launch xfce4-screenshooter, capture whatever region, at whatever dalay, then select `Copy to the clipboard`, click OK. Clipboard has no image. but /tmp/ has a newly created `Screenshot_<date>_<time>.png`