New KDE user (Plasma 5.9.4). When using the "Rectangular Region" option of Spectacle, the rectangular cursor-drawn line that I expect to see is invisible! I have to guess where the lines should be in order to use the function at all! This happens regardless of the theme.

Any help? I'm on Arch Linux 64bit.

Are you using the Spectacle 'Light Background For Rectangular Region' option ?

Spectacle > Save & Exit > Preferences

Use a light background color to mask the cropped-out area in the rectangular region selector. This may make dark cursors easier to see.

After the Bug 378685 - Improve the contrast of the slection '+' cursor - can hardly see it : https://bugs.kde.org/show_bug.cgi?id=378685 there was an update to the Spectacle docbook - https://phabricator.kde.org/D5432

The latest version of the Spectacle Handbook: https://docs.kde.org/trunk5/en/kdegraph ... index.html
Configure options: https://docs.kde.org/trunk5/en/kdegraph ... 04s02.html

I am not using that option (nor does selecting it make any difference).
Thanks!

I have same issue on Debian Stretch (9) recently installed
I am using nouveau driver on a nvidia GeForce GTS 250, if it matters..