I am trying to install RubyGems using 'ruby setup.rb'.  I have
cross-compiled Ruby to target an arm-based machine and have successfully
installed Ruby on it.  

When I run setup.rb, everything looks good until just after the "No
library stubs found" message is shown.  At this point, I am getting a
message that zlib.so cannot be opened.  Here's the full exception:

/usr/local/ruby-1.8.2-arm/ext/zlib/zlib.so:
/usr/local/ruby-1.8.2-arm/ext/zlib/zlib.so: cannot open shared object
file: No such file or directory -
/usr/local/ruby-1.8.2-arm/ext/zlib/zlib.so (LoadError)
        from
/usr/local/ruby-1.8.2-arm/lib/rubygems/custom_require.rb:21:in `require'
        from /usr/local/ruby-1.8.2-arm/lib/rubygems/package.rb:9
        from
/usr/local/ruby-1.8.2-arm/lib/rubygems/custom_require.rb:21:in `require__'
        from
/usr/local/ruby-1.8.2-arm/lib/rubygems/custom_require.rb:21:in `require'
        from /usr/local/ruby-1.8.2-arm/lib/rubygems/builder.rb:1
        from
/usr/local/ruby-1.8.2-arm/lib/rubygems/custom_require.rb:21:in `require__'
        from
/usr/local/ruby-1.8.2-arm/lib/rubygems/custom_require.rb:21:in `require'
        from /usr/local/ruby-1.8.2-arm/lib/rubygems.rb:61:in `manage_gems'
         ... 7 levels...
        from setup.rb:887:in `exec_install'
        from setup.rb:705:in `invoke'
        from setup.rb:674:in `invoke'
        from setup.rb:1352

Do I have to load zlib manually?  I see a zlib.c source file in the
ext/zlib directory, but I don't see zlib.so.

I have been working on getting Ruby and RubyGems (and eventually Rails)
installed on this machine since yesterday morning, and so far it's been
a much bigger chore than I would have expected.  I would appreciate any
help anyone has to offer.

Thanks,
Shawn