checking For uintXX_t types... yes checking For socklen_t... ./configure: socklen_t: not found ./configure: foo: not found checking For size_t... ./configure: size_t: not found ./configure: foo: not found checking for dlopen in -ldl... yes The problem is: AC_MSG_CHECKING([For size_t]) AC_TRY_COMPILE( [#include <sys/types.h>], [#include <sys/socket.h>], [size_t foo; foo = 1235;], [ AC_DEFINE(HAVE_SIZE_T) AC_MSG_RESULT(yes) ], [AC_MSG_RESULT(no)] ) The syntax should be: AC_TRY_COMPILE([<include files>],[<code>],[<success>],[<fail>]) But the configure.in has each include in a seperate [] ... Marc G. Fournier marc.fournier at acadiau.ca Senior Systems Administrator Acadia University "These are my opinions, which are not necessarily shared by my employer"