You know?

You made me think about this for a minute and I think I figured it out.

Use the circle pin to draw the circle.

Then use the select tool to select the circle that you drew.

Then use the grow/shrink tool to shrink the selection by however many pixels thick you want the circle to be.

Then use the erase tool to erase all the parts of the circle that you don’t want.

Easy peasy.

Thank you. I was afraid I was being a little too subtle.

Kubuntu isn’t too bad

You can also use the brush tool and just draw a circle that’s completely filled in at whatever size you want and then remove the inner portion that you don’t want by switching to the erase tool and then shrinking the size of the circle brush to what you don’t need and clicking directly in the center of the circle.