poudriere + ZFS + NFS -> chown: /usr/local/poudriere/data/.m/rpi5-freebsd143-custom/01/.npkg: Operation not permitted

Hi,

I have the following setup of jails with poudriere running in Jenkins:

pkg jail: running lighttpd exporting the poudriere UI. This jail NFS exports /usr/local/poudriere/data/logs/bulk and /usr/local/poudriere/data/packages.

poudriere jail 1: running poudriere+ZFS and it NFS mounts /usr/local/poudriere/data/logs/bulk and /usr/local/poudriere/data/packages from the pkg jail.
poudriere jail 1: running poudriere (no ZFS) and it NFS mounts /usr/local/poudriere/data/logs/bulk and /usr/local/poudriere/data/packages from the pkg jail.

The mounts work, I can access the files on the command line.

But on the pourdriere with ZFS at the end of the first build I get this error:
[00:01:32] ====> Compressing man pages (compress-man)
[00:01:32] ===>   Installing ldconfig configuration file
[00:01:32] ===========================================================================
[00:01:32] chown: /usr/local/poudriere/data/.m/rpi5-freebsd143-custom/01/.npkg: Operation not permitted
[00:01:32] =======================<phase: package        >============================
[00:01:32] ===== env: 'PKG_NOTES=build_timestamp ports_top_git_hash ports_top_checkout_unclean port_checkout_unclean built_by' 'PKG_NOTE_build_timestamp=2025-10-28T13:33:27+00:00' 'PKG_NOTE_ports_top_git_hash=d72ccf55aa06' 'PKG_NOTE_ports_top_checkout_unclean=no' 'PKG_NOTE_port_checkout_unclean=no' 'PKG_NOTE_built_by=poudriere-git-3.4.99.20251006' NO_DEPENDS=yes USER=nobody UID=65534 GID=65534
[00:01:32] ===>  Building packages for pkg-2.3.1
[00:01:32] mkdir: /.npkg/All: Permission denied
[00:01:32] *** Error code 1
Any idea why this happens?
This directory is not NFS mounted, so why would it give an error here?

Regards,
Ronald.