Cause and solution are described in some detail here: https://www.reddit.com/r/zfs/comments/bicu1g/zfs_send_issues_a_zfs_ioctl_which_fails_with/em1rj9r/?utm_source=share&utm_medium=web2x -- the cause was a config error, and the solution was to correct the config error.
But, when an ioctl() call fails with EINVAL, this should not cause a coredump in the zfs tools. IMO that's still a bug.
