Failed to install ruby-ldap on Snow Leo

I tried开发者_JS百科 to install ruby-ldap on Snow Leo, but it failed:

~/WorkingFolder/temp/test$ sudo gem install ruby-ldap
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing ruby-ldap:
    ERROR: Failed to build gem native extension.

/opt/local/bin/ruby extconf.rb
--with-openldap2
checking for ldap.h... no
checking for lber.h... no
checking for ldap_ssl.h... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/opt/local/bin/ruby
    --with-netscape
    --without-netscape
    --without-netscape
    --with-openldap1
    --without-openldap1
    --without-openldap1
    --with-openldap2
    --without-openldap2
    --without-openldap2
    --with-wldap32
    --without-wldap32
    --without-wldap32
    --with-ldap-dir
    --without-ldap-dir
    --with-ldap-include
    --without-ldap-include=${ldap-dir}/include
    --with-ldap-lib
    --without-ldap-lib=${ldap-dir}/lib
    --with-ldap-dir
    --without-ldap-dir
    --without-ldap-dir
    --with-ldap
    --without-ldap
    --without-ldap
    --with-libresolv
    --without-libresolv
    --without-libresolv
    --with-libcrypto
    --without-libcrypto
    --without-libcrypto
    --with-libssl
    --without-libssl
    --without-libssl
    --with-libpthread
    --without-libpthread
    --without-libpthread
    --with-libnsl
    --without-libnsl
    --without-libnsl
    --with-liblber
    --without-liblber
    --without-liblber
    --with-libldap_r
    --without-libldap_r
    --without-libldap_r
    --with-libldap
    --without-libldap
    --without-libldap
can't find ldap.h and lber.h
use the option '--with-ldap-dir'!


Gem files will remain installed in /opt/local/lib/ruby/gems/1.8/gems/ruby-ldap-0.9.11 for inspection.
Results logged to /opt/local/lib/ruby/gems/1.8/gems/ruby-ldap-0.9.11/gem_make.out

Anyone know how to fix this, please help!!

Thanks

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The LDAP development headers are unavailable on your system and ruby-ldap requires those headers. Installing Apple's Development Tools (XCode) should install those development headers also. Could you install the Developer Tools and retry installing ruby-ldap?