how to enable ldap authentication - Mailing list pgsql-general

I was trying to enable ldap authentication for 9.1 server.
I did:
./configure --with-ldap --with-openssl
make
sudo make install

And got these files installed:
ll /usr/local/pgsql/bin/

-rwxr-xr-x  1 root root   54811 Oct 24 10:27 clusterdb
-rwxr-xr-x  1 root root   55860 Oct 24 10:27 createdb
-rwxr-xr-x  1 root root   58885 Oct 24 10:27 createlang
-rwxr-xr-x  1 root root   59094 Oct 24 10:27 createuser
-rwxr-xr-x  1 root root   54438 Oct 24 10:27 dropdb
-rwxr-xr-x  1 root root   58811 Oct 24 10:27 droplang
-rwxr-xr-x  1 root root   54440 Oct 24 10:27 dropuser
-rwxr-xr-x  1 root root  712806 Oct 24 10:27 ecpg
-rwxr-xr-x  1 root root   81110 Oct 24 10:27 initdb
-rwxr-xr-x  1 root root   42019 Oct 24 10:27 pg_basebackup
-rwxr-xr-x  1 root root   30484 Oct 2 4 10:27 pg_config
-rwxr-xr-x  1 root root   26557 Oct 24 10:27 pg_controldata
-rwxr-xr-x  1 root root   40733 Oct 24 10:27 pg_ctl
-rwxr-xr-x  1 root root  323414 Oct 24 10:27 pg_dump
-rwxr-xr-x  1 root root   76002 Oct 24 10:27 pg_dumpall
-rwxr-xr-x  1 root root   34863 Oct 24 10:27 pg_resetxlog
-rwxr-xr-x  1 root root  141783 Oct 24 10:27 pg_restore
-rwxr-xr-x  1 root root 5524481 Oct 24 10:27 postgres
lrwxrwxrwx  1 root root       8 Oct 24 10:27 postmaster -> postgres
-rwxr-xr-x  1 root root  414148 Oct 24 10:27 psql
-rwxr-xr-x  1 root root   56027 Oct 24 10:27 reindexdb
-rwxr-xr-x  1 root root   33659 Oct 24 10:27 vacuumdb

It seemed the executable was compiled with ldap:

ldd /usr/local/pgsql/bin/postgres
        libpam.so.0 =&g t; /lib64/libpam.so.0 (0x0000003d12300000)
        libssl.so.0.9.8 => /usr/lib/libssl.so.0.9.8 (0x0000003d10200000)
        libcrypto.so.0.9.8 => /usr/lib/libcrypto.so.0.9.8 (0x0000003d10c00000)
        libgssapi_krb5.so.2 => /usr/lib64/libgssapi_krb5.so.2 (0x0000003d11200000)
        libcrypt.so.1 => /lib64/libcrypt.so.1 (0x0000003d10600000)
        libdl.so.2 => /lib64/libdl.so.2 (0x0000003d10000000)
        libm.so.6 => /lib64/tls/libm.so.6 (0x0000002a95567000)
        libldap-2.2.so.7 => /usr/lib64/libldap-2.2.so.7 (0x0000002a956ed000)                           <----
        libc.so.6 => /lib64/tls/libc.so.6 (0x0000003d0fd00000)
        libaudit.so.0 => /lib64/libaudit.so.0 (0x0000003d11f00000)
        libkrb5.so.3 => /usr/lib64/libkrb5.so.3 (0x0000003d11600000)
        libk5crypto.so.3 => /usr/lib64/libk5crypto.so.3 (0x0000003d11000000)
        libcom_err.so.2 => /lib64/libcom_err.so.2 (0x0000002a95825000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003d0fb00000)
        liblber-2.2.so.7 => /usr/lib64/liblber-2.2.so.7 (0x0000002a95927000)
        libresolv.so.2 => /lib64/libresolv.so.2 (0x0000003d10a00000)
        libsasl2.so.2 => /usr/lib64/libsasl2.so.2 (0x0000002a95a 36000)
        libssl.so.4 => /lib64/libssl.so.4 (0x0000003d10800000)
        libcrypto.so.4 => /lib64/libcrypto.so.4 (0x0000003d11800000)
        libz.so.1 => /usr/lib64/libz.so.1 (0x0000003d10400000)

ldd /usr/local/pgsql/bin/pg_ctl
        libpq.so.5 => /usr/local/pgsql/lib/libpq.so.5 (0x0000002a95557000)
        libpam.so.0 => /lib64/libpam.so.0 (0x0000003d12300000)
        libssl.so.0.9.8 => /usr/lib/libssl.so.0.9.8 (0x0000003d10200000)
        libcrypto.so.0.9.8 => /usr/lib/libcrypto.so.0.9.8 (0x0000003d10c00000)
        libgssapi_krb5.so.2 => /usr/lib64/libgssapi_krb5.so.2 (0x0000003d11200000)
        l ibz.so.1 => /usr/lib64/libz.so.1 (0x0000003d10400000)
        libreadline.so.4 => /usr/lib64/libreadline.so.4 (0x0000003d11400000)
        libtermcap.so.2 => /lib64/libtermcap.so.2 (0x0000002a9568f000)
        libcrypt.so.1 => /lib64/libcrypt.so.1 (0x0000003d10600000)
        libdl.so.2 => /lib64/libdl.so.2 (0x0000003d10000000)
        libm.so.6 => /lib64/tls/libm.so.6 (0x0000002a95793000)
        libc.so.6 => /lib64/tls/libc.so.6 (0x0000003d0fd00000)
        libldap_r-2.2.so.7 => /usr/lib64/libldap_r-2.2.so.7 (0x0000002a9591a000)     <------
        libpthread.so.0 => /lib64/tls/libpthread.so.0 (0x0000002a95a59000)
 &n bsp;      libaudit.so.0 => /lib64/libaudit.so.0 (0x0000003d11f00000)
        libkrb5.so.3 => /usr/lib64/libkrb5.so.3 (0x0000003d11600000)
        libk5crypto.so.3 => /usr/lib64/libk5crypto.so.3 (0x0000003d11000000)
        libcom_err.so.2 => /lib64/libcom_err.so.2 (0x0000002a95b70000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003d0fb00000)
        liblber-2.2.so.7 => /usr/lib64/liblber-2.2.so.7 (0x0000002a95c72000)
        libresolv.so.2 => /lib64/libresolv.so.2 (0x0000003d10a00000)
        libsasl2.so.2 => /usr/lib64/libsasl2.so.2 (0x0000002a95d81000)
        libssl.so.4 => /lib64/libssl.so.4 (0x0000003d10800000)
 &nbs p;      libcrypto.so.4 => /lib64/libcrypto.so.4 (0x0000003d11800000)

But when I ran pg_ctl start, it exits without listening any port and I got this:
tail postgresql-2011-10-24_104954.log
LOG:  invalid authentication method "ldap": not supported by this build
CONTEXT:  line 97 of configuration file "/usr/local/pgsql/databases/tudouapi/pg_hba.conf"
FATAL:  could not load pg_hba.conf

Anyone be so kind to enlighten me !!