These shavings kept clogging the intake to the dust collector. After clearing the intake and shaking out the hose about twenty times, I needed something better, right away.
This worked. I taped up the edges of the box, cut two holes, cut off a length of hose, and was able to run the planer until the box filled. Then I emptied the box, taped it up again, and ran the planer until I was finished.