I am unsure whether to report the following as a bug, because it seems fixed in the current "Krita Plus". I tried to find similar things in the bug tracker but could not find any. Maybe someone here can tell me whether I should still report this?

Steps to reproduce:
1. In an empty image, create a vector layer.
2. With the line tool, draw an exactly vertical line.
3. Use the select tool, click on the line.
4. Move the cursor onto the top handle of the line such that it becomes a vertical resize cursor.
5. While holding down the shift key, click on that handle.

Result:
Krita gets stuck with 100% CPU load.

Affected:
- krita deb package 1:4.1.7+dfsg-1+b1 from Debian Buster
- current krita-4.2.9-x86_64.appimage from krita.org

Not affected:
- current "Krita Plus" version krita-4.3.0-prealpha-eca4f7f-x86_64.appimage.

Yes, that was reported and fixed. However, apparantly not backported, so it never got in 4.2.9. It'll be in the next stable release (which is 4.3). We don't have an LTS system, just stable and master, and it is recommended to use the latest stable whenever possible.

Thank you for the superquick reply, good to know.

And thanks for all your work on and for krita!