-AC_ARG_ENABLE(docygen, [ --enable-doxygen Use doxygen to build documentation (default=auto)], enable_doxygen="$enableval",
-enable_doxygen=auto)
+AC_ARG_ENABLE(docygen,
+ [ --enable-doxygen Use doxygen to build documentation (default=auto)],
+ [enable_doxygen="$enableval"],
+ [enable_doxygen=auto])