zfs failure "cannot unmount" when stopping the container

[kit-ty-kate]

Steps to reproduce:

host# docker run --rm -it kwiat/freebsd:13.0-RELEASE sh
container# pkg install git
container# ^D

[kit-ty-kate]

If you wait a little before exiting, the problem does not occur.

[kit-ty-kate]

The same thing happens between intermediate containers:

FROM kwiat/freebsd:13.0-RELEASE
RUN pkg install -y git
# same zfs error happens here
RUN git clone git://github.com/ocaml/opam.git

[kit-ty-kate]

More logs from dockerd when a docker build failed after having written many things on disk, in case this helps: