From: autoconf-bounces+scott.b.drummonds=intel.com@xxxxxxx > I just upgraded to a brand new version of Autoconf (2.59) and > 'configure' is now failing where it previously did not. Specifically, > it is unable to verify the presence of any of the ANSI C header files. After a couple of e-mails and a little trial-and-error, I've narrowed down the scope of this problem: ac_objext is being set correctly by configure. However, it's not occurring until well after the ANSI C headers have been checked. As such, the check--which relies on this variable's value--is failing. First, what macro is generating the "checking for ANSI C header files..." test? (My environment is very large and trial-and-error elimination may take me a very long time.) I'd like to reorganize my configuration around this problem. Second, which macro is generating the "checking for suffix of object files..." test? Moving this test to a time before the header check may be another way of fixing this problem. Third, is this the intended operation of autoconf? I haven't read any documentation that states an explicit order in which tests must be invoked, but I may have missed something. If I have not missed something, either the documentation should be updated or this order-dependent behavior should be modified. Thanks in advance, Scott