I've recently been struggling with my mac laptop not having any disk space left. Each time I've deleted whatever large files I had in Download or any other out of date stuff - thinking that I was just being a heavy disk user.
But - it kept happening - so I actually dug into it with du.
It turns out I had gigabytes and gigabytes in
So I deleted all images and containers - but this file didn't get any smaller.
Google lead me to this github issue which covers this behaviour.
For me - it's simplest just to do a client reset (since this docker is only used for development) - but I hope that they fix this fairly soon.