root@obs# apt-get install zlib1g
root@obs# apt-get install zlib1g-dev
hao@obs% ruby extconf.rb                           [~/src/ruby/ruby-zlib-0.6.0]
checking for deflateReset() in -lz... yes
checking for zlib.h... yes
checking for rb_block_given_p()... yes
checking for rb_str_buf_new()... yes
checking for rb_io_print()... yes
checking for rb_io_printf()... yes
checking for rb_io_puts()... yes
checking for rb_io_addstr()... yes
checking for rb_define_alloc_func()... yes
checking for rb_undef_alloc_func()... yes
checking for kind of operating system... Unix
creating Makefile
hao@obs% make                                      [~/src/ruby/ruby-zlib-0.6.0]
gcc -fPIC -g -O2  -I. -I/usr/local/lib/ruby/1.8/powerpc-linux -I/usr/local/lib/ruby/1.8/powerpc-linux -I. -DHAVE_ZLIB_H -DHAVE_RB_BLOCK_GIVEN_P -DHAVE_RB_STR_BUF_NEW -DHAVE_RB_IO_PRINT -DHAVE_RB_IO_PRINTF -DHAVE_RB_IO_PUTS -DHAVE_RB_IO_ADDSTR -DHAVE_RB_DEFINE_ALLOC_FUNC -DHAVE_RB_UNDEF_ALLOC_FUNC  -DOS_CODE=OS_UNIX -c zlib.c
gcc -shared  -L"/usr/local/lib" -o zlib.so zlib.o  -lz  -ldl -lcrypt -lm   -lc
hao@obs% hsu                                       [~/src/ruby/ruby-zlib-0.6.0]
root@obs# make install                             [~/src/ruby/ruby-zlib-0.6.0]
install -c -p -m 0755 zlib.so /usr/local/lib/ruby/site_ruby/1.8/powerpc-linux
root@obs#
hao@obs% cd rubygems-0.8.10
root@obs# ruby setup.rb
---> bin
<--- bin
---> lib
---> lib/rubygems
<--- lib/rubygems
<--- lib
---> bin
<--- bin
---> lib
---> lib/rubygems
<--- lib/rubygems
<--- lib
rm -f InstalledFiles
---> bin
mkdir -p /usr/local/bin/
install gemwhich /usr/local/bin/
install gem /usr/local/bin/
install gem_server /usr/local/bin/
install generate_yaml_index.rb /usr/local/bin/
install update_rubygems /usr/local/bin/
<--- bin
---> lib
mkdir -p /usr/local/lib/ruby/site_ruby/1.8/
install ubygems.rb /usr/local/lib/ruby/site_ruby/1.8/
install rubygems.rb /usr/local/lib/ruby/site_ruby/1.8/
install gemconfigure.rb /usr/local/lib/ruby/site_ruby/1.8/
---> lib/rubygems
mkdir -p /usr/local/lib/ruby/site_ruby/1.8/rubygems
install specification.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install builder.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install command.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install config_file.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install custom_require.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install doc_manager.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install format.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install cmd_manager.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install gem_runner.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install installer.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install loadpath_manager.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install old_format.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install open-uri.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install package.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install remote_installer.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install rubygems_version.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install source_index.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install deployment.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install timer.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install user_interaction.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install validator.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install version.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install gem_commands.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
install dependency_list.rb /usr/local/lib/ruby/site_ruby/1.8/rubygems
<--- lib/rubygems
<--- lib

As of RubyGems 0.8.0, library stubs are no longer needed.
Searching $LOAD_PATH for stubs to optionally delete (may take a while)...
...done.
No library stubs found.

Successfully built RubyGem
Name: sources
Version: 0.0.1
File: sources-0.0.1.gem