rude hack to proceed on zoneadm attach error

I have two zones on my build host. One is build zone, serving IPS repository for the whole host,  so I have to be very careful with its updates and another - test one. I wished to update test zone, so issued

# zoneadm -z zonename detach
# zoneadm -z zonename attach -u

and noticed that I detached build zone with repository. zoneadm launched pkg, pkg worked for a while, and then it said:

Evaluation: Packages in zone zonename are out of sync with the global zone. To proceed, retry with the -u flag. 
Result: Attach Failed.

What a hell! NGZ and GZ were in sync... At least both of them were latest /hipster. So I removed all publishers served by this zone from host and zone config.  The same reaction.
After grepping for this message in  /usr/lib/brand/ipkg/attach I found that this message is produced in  the following part of the script ($m_need_update message).

#
# Bring the ngz entire incorporation into sync with the gz as follows:
# - First compare the existence of entire in both global and non-global
#   zone and update the non-global zone accordingly.
# - Then, if updates aren't allowed check if we can attach because no
#   updates are required. If we can, then we are finished.
# - Finally, we know we can do updates and they are required, so update
#   all the non-global zone incorporations using the list we gathered
#   from the global zone earlier.
#

if [[ -z $gz_entire_fmri && -n $ngz_entire_fmri ]]; then
        if [[ $allow_update == 1 ]]; then
                LC_ALL=C $PKG uninstall entire || pkg_err_check "$f_update"
        else
                log "\n$m_need_update" "$ZONENAME"
                EXIT_CODE=$ZONE_SUBPROC_NOTCOMPLETE
                exit $EXIT_CODE
    fi
fi


if [[ $allow_update == 0 ]]; then
        LC_ALL=C $PKG install --accept --no-refresh -n $incorp_list
        if [[ $? == 0 ]]; then
                log "\n$m_complete"
                EXIT_CODE=$ZONE_SUBPROC_OK
                exit $EXIT_CODE
        else
                log "\n$m_need_update" "$ZONENAME"
                EXIT_CODE=$ZONE_SUBPROC_NOTCOMPLETE
                exit $EXIT_CODE
        fi
fi

I've just commented all these checks out and after this zone attach succeed. Zone is working now and I'm glad I don't have to reinstall my build zone....