Something

AC_ARG_ENABLE(kdnssd-avahi, [  --enable-kdnssd-avahi     require avahi ],  with_with_kdnssd_avahi=$enableval, with_with_kdnssd_avahi=yes)
if test "x$with_kdnssd_avahi" != "xno"; then
	PKG_CHECK_MODULES([avahi-client >= 0.6 avahi-qt3 >= 0.6]);
	AC_CONFIG_FILES([kdnssd-avahi/Makefile]);

I get this:

./configure: line 42369: syntax error near unexpected token `;'
./configure: line 42369: `;'