I do not understand why I get this message.
Suppose I have two points, (1 0 0) and (2 0 0). I set the line length to exactly 1 but the error still pops up.
Why is that the case?
I was the one making the mistake. I THOUGHT I had (1 0 0) and (2 0 0) but actually that was not the case :-)
So now the warning makes sense to me.