gtkbuilder.*.xml

[Matt Postiff <postiffm gmail com>]

I have a bunch of files called gtkbuilder.*.xml in my gtk2 program.

I am having trouble on msys2 to use gettext to extract strings from them 
for i18n. xgettext says that it doesn't recognize the extension xml.

Are these files named in a non-standard way? Should they be rather 
called gtkbuilder.*.glade or gtkbuilder.*.ui?

Thanks,

Matt

Here's an example:

$ cat ../templates/gtkbuilder.timednotifywindow.xml
<?xml version="1.0"?>
<interface>
  <!-- interface-requires gtk+ 2.12 -->
  <!-- interface-naming-policy project-wide -->
  <object class="GtkWindow" id="window">
    <property name="title" translatable="yes">Notification</property>
    <property name="resizable">False</property>
    <property name="window_position">center-always</property>
    <property name="type_hint">notification</property>
    <property name="skip_taskbar_hint">True</property>
    <property name="skip_pager_hint">True</property>
    <property name="decorated">False</property>
    <property name="deletable">False</property>
    <child>
      <object class="GtkLabel" id="label">
        <property name="visible">True</property>
        <property name="xpad">60</property>
        <property name="ypad">60</property>
      </object>
    </child>
  </object>
</interface>