How marks coordinates work?

[arkadiuszwojcik]

I am confused with marks coordinates. I am using 0.2.2 and doc is saying that first parameter is place position, and second is direction, so I test following code:

  mark((0,0), (0,1), symbol: "stealth", scale: 1, fill: black)
  mark((0,0), (0,3), symbol: ">", scale: 1, fill: black)

I would expect both marks to be in same place (0,0) and point in same direction. But somehow second parameter effect their position and they end up in different places:

Moreover I would like to write function that places mark at the center of line, but because of that bug? It doesn't work. Here is my function:

let draw-arrow-line(start, end) = {
  line(start, end)
  mark((start, 0.5, end), end, symbol: "stealth", scale: 1, fill: black)
}

Can someone advice what I am doing wrong?

[fenjalien]

Turns out this is a bug, #557 was opened to resolve this.