https://bugs.gentoo.org/906227
https://github.com/dajobe/raptor/issues/59
https://github.com/dajobe/raptor/pull/58

--- raptor2-2.0.16/src/raptor_libxml.c.orig
+++ raptor2-2.0.16/src/raptor_libxml.c
@@ -246,10 +246,11 @@
     
     ret->owner = 1;
 
-#if LIBXML_VERSION >= 20627
+#if LIBXML_VERSION >= 20627 && LIBXML_VERSION < 21100
     /* Checked field was released in 2.6.27 on 2006-10-25
      * http://git.gnome.org/browse/libxml2/commit/?id=a37a6ad91a61d168ecc4b29263def3363fff4da6
      *
+     * and was later removed in version 2.11.0
      */
 
     /* Mark this entity as having been checked - never do this again */