segfaulting love2d with coroutines and user data

main.lua

function love.load(args)
  love.physics.setMeter(60)
  World = love.physics.newWorld(0, 10 * 16, true)

  World:setCallbacks(function(fixture_a, fixture_b, contact)
    print(fixture_a, fixture_b)
    local data_a, data_b = fixture_a:getUserData(), fixture_b:getUserData()
    print("I never run because of segfault.")
  end)

  coroutine_function = coroutine.create(function()
    for i=1,3 do
      local body = love.physics.newBody(World, love.graphics.getWidth() / 2, love.graphics.getHeight() - 100 + 30 * i, "static")
      local shape = love.physics.newRectangleShape(love.graphics.getWidth(), 20)
      local fixture = love.physics.newFixture(body, shape)
      fixture:setUserData("test" .. i)
      coroutine.yield()
    end
  end)

  local body = love.physics.newBody(World, love.graphics.getWidth() / 2, 30, "dynamic")
  local shape = love.physics.newRectangleShape(20, 20)
  local fixture = love.physics.newFixture(body, shape)
end

function love.update(dt)
  World:update(dt)
  if coroutine.status(coroutine_function) ~= "dead" then
    print(coroutine.resume(coroutine_function))
  end
end

function love.keypressed(key, unicode)
  if key == "escape" then
    love.event.push("quit")
  end
end

function love.draw()
  love.graphics.setColor(0, 255, 0)
  for _, body in ipairs(World:getBodyList()) do
    for _, fixture in ipairs(body:getFixtureList()) do
      local shape = fixture:getShape()
      love.graphics.polygon("fill", body:getWorldPoints(shape:getPoints()))
    end
  end
end