+ AC_MSG_WARN([
+** Djvu support is disabled since recent version of djvulibre
+** library was not found. To get proper djvu support you need to
+** install development version of djvulibre. You can get it from
+** anonymous CVS server on djvulibre.sf.net. Just use something
+** like:
+
+** cvs -d :pserver:anonymous@cvs.sourceforge.net:/cvsroot/djvu co djvulibre-3.5
+])