autotools temporary files

Question

I'm trying to debug an autotools problem for an open-source project, which is failing at the configure step. I'd like to see the code/executable that configure is trying to run.

However, the config.log only shows that something failed (not the code it tried to compile) and I don't know where the temporary executables are being stored (and they're probably promptly deleted anyway).

Is there a way get autotools to keep its temporary files around? It doesn't matter at which level this is specified-- either with args to configure, args to autoconf when it generates configure, or even some m4 invocation.

EDIT When something fails, configure.log looks like this:

configure:3285: checking whether we are cross compiling
configure:3293: gcc -o conftest.exe -DU_STATIC_IMPLEMENTATION -O3   conftest.c  >&5
configure:3297: $? = 0
configure:3304: ./conftest
configure:3308: $? = 1
configure:3315: error: in `/home/bobthebuilder/Development/icu/build':
configure:3317: error: cannot run C compiled programs.
If you meant to cross compile, use `--host'.
See `config.log' for more details

Answer 1

As of Autoconf 2.71, this is already done automatically. Search the config.log file for the string "configure: failed program was:"; the listing of the failed test program is shown in full following that line, e.g.:

configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "GNU Hello"
| #define PACKAGE_TARNAME "hello"
| #define PACKAGE_VERSION "2.10"
| #define PACKAGE_STRING "GNU Hello 2.10"
| #define PACKAGE_BUGREPORT "[email protected]"
| #define PACKAGE_URL "http://www.gnu.org/software/hello/"
| #define PACKAGE "hello"
| #define VERSION "2.10"
| /* end confdefs.h.  */
| 
| int
| main ()
| {
| 
|   ;
|   return 0;
| }