Did you read the actual straight line tutorial? It's here:
Simon Roberts wrote:
Nutshell version: no, I'd not seen this, yes, so far as I can make out,
I'm doing what the tutorial says, but no, I don't get any line.
I get two crosshairs and a line joining the two as I move the mouse
while holding shift (I can constrain the line to certain angles with
control too) but when I release shift, the whole thing goes away.
I'm using 2.3.8. I must admit I did not find that tutorial explicit enough,
or perhaps the method has changed. I had to do this:
1. One left click and release of the mouse at the point you want the start
of the line.
2. Hold shift down. Hold control down as well if you want constrained
3. Move the mouse - a guide line will be drawn - without clicking, to where
you want the end of the line.
4. Click and release the mouse button. The line will be drawn.
5. Release the shift key.
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