Couchbase Ruby Client Heroku build error.

couchbase-ruby-client-heroku-error

       Installing couchbase (1.2.3)
       Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
       /tmp/build_3h7fjy5bd2ir/vendor/ruby-2.0.0/bin/ruby extconf.rb --with-libcouchbase-dir=/app/vendor/couchbase
       checking for lcb_verify_compiler_setup() in -lcouchbase... no
       **********************************************************************
       You must install libcouchbase >= 2.0.0beta3. See http://www.couchbase.com/develop/ for more details
       **********************************************************************
       *** 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=/tmp/build_3h7fjy5bd2ir/vendor/ruby-2.0.0/bin/ruby
       --with-libcouchbase-dir
       --with-libcouchbase-include
       --without-libcouchbase-include=${libcouchbase-dir}/include
       --with-libcouchbase-lib
       --without-libcouchbase-lib=${libcouchbase-dir}/
       --with-couchbaselib
       --without-couchbaselib
       Gem files will remain installed in /tmp/build_3h7fjy5bd2ir/vendor/bundle/ruby/2.0.0/gems/couchbase-1.2.3 for inspection.
       Results logged to /tmp/build_3h7fjy5bd2ir/vendor/bundle/ruby/2.0.0/gems/couchbase-1.2.3/ext/couchbase_ext/gem_make.out
       An error occurred while installing couchbase (1.2.3), and Bundler cannot
       continue.
       Make sure that `gem install couchbase -v '1.2.3'` succeeds before bundling.
 !
 !     Failed to install gems via Bundler.
 !
 !     Heroku push rejected, failed to compile Ruby/rails app