I have a button which I need to hide if the user is a superuser (admin). My problem is that when I'm using xpath to include the attrs, nothing is working as expected. My code is:

<record id="wms_stock_view_move_form" model="ir.ui.view">

            <field name="name">wms.stock.view.move.form</field>

            <field name="model">stock.move</field>

            <field name="inherit_id" ref="stock.view_move_form" />

            <field name="arch" type="xml">

                <field name="location_id" position="attributes">

                    <attribute name="domain">[('name','!=', 'Scrapped')]</attribute>

                </field>

                <field name="location_id" position="after">

                    <field name="is_superuser"/>

                </field>

                <field name="location_dest_id" position="attributes">

                    <attribute name="domain">[('name','!=', 'Scrapped')]</attribute>

                </field>

                <xpath expr='//form[@string="Stock Moves"]' position='attributes'>

                    <attribute name="create">false</attribute>

                    <attribute name="edit">false</attribute>

                    <attribute name="delete">false</attribute>

                </xpath>

                <xpath expr="//button[@name='action_cancel']" position="attributes">

                    <attribute name="attrs">{'invisible':[('is_superuser','=', True)]}</attribute>

                </xpath>

            </field>

        </record>

is_superuser = fields.Boolean(compute='_is_super_user')

def _is_super_user(self):

    if self._uid == SUPERUSER_ID:
        self.is_superuser = True
    else:
        self.is_superuser = False

The original code for the button, in its original view is:

<button name="action_cancel" states="draft,assigned,confirmed" string="Cancel Move" type="object"/>

any idea, what I'm doing wrong ? Thanks in advance.