Unpacking libruby1.9.1 (from .../libruby1.9.1_1.9.3.0-1ubuntu2_amd64.deb) ...
Selecting previously unselected package ruby1.9.1.
Unpacking ruby1.9.1 (from .../ruby1.9.1_1.9.3.0-1ubuntu2_amd64.deb) ...
Selecting previously unselected package ruby-rubyzip2.
Unpacking ruby-rubyzip2 (from .../ruby-rubyzip2_2.0.1-0ubuntu4_all.deb) ...
Selecting previously unselected package ruby-highline.
Unpacking ruby-highline (from .../ruby-highline_1.6.2-1_all.deb) ...
Selecting previously unselected package libhighline-ruby1.9.1.
Unpacking libhighline-ruby1.9.1 (from .../libhighline-ruby1.9.1_1.6.2-1_all.deb) ...
Selecting previously unselected package ruby-mime-types.
Unpacking ruby-mime-types (from .../ruby-mime-types_1.17.2-1_all.deb) ...
Selecting previously unselected package ruby-rest-client.
Unpacking ruby-rest-client (from .../ruby-rest-client_1.6.7-1_all.deb) ...
Selecting previously unselected package ruby-terminal-table.
Unpacking ruby-terminal-table (from .../ruby-terminal-table_1.4.2-0ubuntu3_all.deb) ...
Selecting previously unselected package ruby-json-pure.
Unpacking ruby-json-pure (from .../ruby-json-pure_1.5.1-0ubuntu3_all.deb) ...
dpkg: error processing /var/cache/apt/archives/ruby-json-pure_1.5.1-0ubuntu3_all.deb (--unpack):
 trying to overwrite '/usr/lib/ruby/vendor_ruby/json.rb', which is also in package ruby-json 1.6.3-1