Hi everybody,

I'm creating a custom addon module customizing the theme of Odoo.
I'm trying to customize Odoo icons for all standard addons, even if they are not installed.

I try to customize, for example, the calendar icon:

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <record id="calendar.mail_menu_calendar" model="ir.ui.menu">
            <field name="web_icon">my_theme,static/icons/calendar.png</field>
            <field name="name">Calendar</field>
        </record>
    </data>
</odoo>

When I launch odoo, it gives me the following error:

2019-12-27 13:28:21,079 48627 ERROR odoo werkzeug: Error on request:
...
  File "/Users/user/odoo/odoo/tools/convert.py", line 255, in _test_xml_id
    assert modcnt == 1, """The ID "%s" refers to an uninstalled module""" % (xml_id,)
odoo.tools.convert.ParseError: "The ID "calendar.mail_menu_calendar" refers to an uninstalled module" while parsing /Users/user/custom-addons/my_theme/views/icons.xml:9, near
<record id="calendar.mail_menu_calendar" model="ir.ui.menu">
            <field name="web_icon">my_theme,static/icons/calendar.png</field>
            <field name="name">Calendar</field>
        </record>

How can i add customized icons even if a module is not (yet) installed?