+tree_index.sgml is not produced now
+--- libvirt-glib-3.0.0/docs/libvirt-glib/Libvirt-glib-docs.xml.orig 2016-10-27 10:56:31.000000000 +0200
++++ libvirt-glib-3.0.0/docs/libvirt-glib/Libvirt-glib-docs.xml 2020-06-21 23:13:46.735155212 +0200
+@@ -16,10 +16,6 @@
+ <xi:include href="xml/libvirt-glib-error.xml"/>
+ <xi:include href="xml/libvirt-glib-event.xml"/>
+ </chapter>
+- <chapter id="object-tree">
+- <title>Object Hierarchy</title>
+- <xi:include href="xml/tree_index.sgml"/>
+- </chapter>
+ <index id="api-index-full">
+ <title>API Index</title>
+ <xi:include href="xml/api-index-full.xml"><xi:fallback /></xi:include>