$ ruby setup.rb config   
Processing the package `cairo' ...
---> lib
<--- lib
---> ext
/usr/local/bin/ruby /home/Administrator/rcairo-1.2.0/packages/cairo/ext/extconf.rb
setup.rb:656: warning: Insecure world writable dir /usr/local/bin, mode 040777
./pkg-config.rb:22: warning: Insecure world writable dir /usr/local/bin, mode 040777
checking for GCC... yes
checking for cairo version (>= 1.2.0)... ./pkg-config.rb:29: warning: Insecure world writable dir /usr/local/bin, mode 040777
./pkg-config.rb:61: warning: Insecure world writable dir /usr/local/bin, mode 040777
no
*** /home/Administrator/rcairo-1.2.0/packages/cairo/ext/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=/home/Administrator/rcairo-1.2.0/packages/cairo/ext
        --curdir
        --ruby=/usr/local/bin/ruby
        --with-pkg-config
        --without-pkg-config
setup.rb:656:in `command': system("/usr/local/bin/ruby" "/home/Administrator/rcairo-1.2.0/packages/cairo/ext/extconf.rb") failed (RuntimeError)