pgbouncer compilation errors

Hi,
I'm trying to install pgbouncer on Linux 64 bits server, and getting a
error about :"conftest.c:8:28: error: ac_nonexistent.h: No such file or
directory".
See bellow all info ,any tips what's missing , i have installed the last
libevent patch:
./configure --prefix=/usr/local --with-libevent=/usr/lib64/
$ ./configure --prefix=/usr/local --with-libevent=/usr/lib64/

## --------- ##
## Platform. ##
## --------- ##

hostname = cvodb0
uname -m = x86_64
uname -r = 2.6.18-92.1.13.el5
uname -s = Linux
uname -v = #1 SMP Wed Sep 24 16:39:16 EDT 2008

/usr/bin/uname -p = unknown
/bin/uname -X = unknown

/bin/arch = x86_64
/usr/bin/arch -k = unknown
/usr/convex/getsysinfo = unknown
/usr/bin/hostinfo = unknown
/bin/machine = unknown
/usr/bin/oslevel = unknown
/bin/universe = unknown

PATH: /usr/kerberos/bin
PATH: /usr/local/bin
PATH: /bin
PATH: /usr/bin

## ----------- ##
## Core tests. ##
## ----------- ##

configure:1753: checking for gcc
configure:1769: found /usr/bin/gcc
configure:1780: result: gcc
configure:2018: checking for C compiler version
configure:2025: gcc --version >&5
gcc (GCC) 4.1.1 20070105 (Red Hat 4.1.1-52)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

configure:2028: $? = 0
configure:2035: gcc -v >&5
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-
threads=posix --enable-checking=release --with-system-zlib
--enable-__cxa_atexit --disable-libunwind-exceptions --enabl
e-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada
--enable-java-awt=gtk --disable-dssi --enable
-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre
--with-cpu=generic --host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)
configure:2038: $? = 0
configure:2045: gcc -V >&5
gcc: '-V' option must have argument
configure:2048: $? = 1
configure:2071: checking for C compiler default output file name
configure:2098: gcc conftest.c >&5
configure:2101: $? = 0
configure:2139: result: a.out
configure:2156: checking whether the C compiler works
configure:2166: ./a.out
configure:2169: $? = 0
configure:2186: result: yes
configure:2193: checking whether we are cross compiling
configure:2195: result: no
configure:2198: checking for suffix of executables
configure:2205: gcc -o conftest conftest.c >&5
configure:2208: $? = 0
configure:2232: result:
configure:2238: checking for suffix of object files
configure:2264: gcc -c conftest.c >&5
configure:2267: $? = 0
configure:2290: result: o
configure:2294: checking whether we are using the GNU C compiler
configure:2323: gcc -c conftest.c >&5
configure:2329: $? = 0
configure:2346: result: yes
configure:2351: checking whether gcc accepts -g
configure:2381: gcc -c -g conftest.c >&5
configure:2387: $? = 0
configure:2486: result: yes
configure:2503: checking for gcc option to accept ISO C89
configure:2577: gcc -c -g -O2 conftest.c >&5
configure:2583: $? = 0
configure:2606: result: none needed
configure:2629: checking how to run the C preprocessor
configure:2669: gcc -E conftest.c
configure:2675: $? = 0
configure:2706: gcc -E conftest.c
conftest.c:8:28: error: ac_nonexistent.h: No such file or directory
configure:2712: $? = 1
configure: failed program was:
| /* confdefs.h. */
| #define PACKAGE_NAME "pgbouncer"
| #define PACKAGE_TARNAME "pgbouncer"
| #define PACKAGE_VERSION "1.2.3"
| #define PACKAGE_STRING "pgbouncer 1.2.3"
| #define PACKAGE_BUGREPORT ""
| /* end confdefs.h. */
| #include <ac_nonexistent.h>
configure:2745: result: gcc -E
configure:2774: gcc -E conftest.c
configure:2780: $? = 0
configure:2811: gcc -E conftest.c
conftest.c:8:28: error: ac_nonexistent.h: No such file or directory
configure:2817: $? = 1
configure: failed program was:
| /* confdefs.h. */
| #define PACKAGE_NAME "pgbouncer"
| #define PACKAGE_TARNAME "pgbouncer"
| #define PACKAGE_VERSION "1.2.3"
| #define PACKAGE_STRING "pgbouncer 1.2.3"
| #define PACKAGE_BUGREPORT ""
| /* end confdefs.h. */