ZFS create crashes my system.

[Pierre Ancelot]

Hello,

I'm trying to figure out how to get out of this situation and most
importantly, to learn from it:

In order to use poudriere, I attempted to create a zpool on a file vdev.
Here is what I did.

mkdir /vdev
mkfile 8g /vdev/disk1               # I was surprised that the space
wasn't showing as used by df
zpool create tank /vdev/disk1

Then, my system crashed and every reboot kept on crashing.
So I started it in single user mode and seen the "tank" pool was
listed as "unavail".

Single user mode won't crash until I mount -rw /

Did I create a race condition having my vdev on / (which uses ZFS)?

How can I recover from this? Cancel my create request (which is
certainly trying to complete everytime it has a chance but never get
there because of the crash)?

Thank you.
Pierre.