raindrops gem install error
===

I am trying to set up Rails and a set of gems on a windows machine, with Aptana as the IDE. When I do a 'bundle install', I get the following message for raindrops 0.10.0.
Please help.

    Installing raindrops (0.10.0) with native extensions
    Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension
    c:/Ruby193/bin/ruby.exe extconf.rb
        checking for mmap() in sys/mman.h... no
        mmap() not found
        *** 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=c:/Ruby193/bin/ruby
                --with-atomic_ops-dir
                --without-atomic_ops-dir
                --with-atomic_ops-include
                --without-atomic_ops-include=${atomic_ops-dir}/include
                --with-atomic_ops-lib
                --without-atomic_ops-lib=${atomic_ops-dir}/lib
        
        
       Gem files will remain installed in c:/Ruby193/lib/ruby/gems/1.9.1/gems/raindrops-0.10.0 for inspection.
        Results logged to c:/Ruby193/lib/ruby/gems/1.9.1/gems/raindrops-0.10.0/ext/raindrops/gem_make.out
        An error occured while installing raindrops (0.10.0), and Bundler cannot continue.
        Make sure that gem install raindrops -v '0.10.0'` succeeds before bundling.

