libxml-rubyのインストールで挫折。

公式ページにあるとおり、gemでインストールしようとしたところエラー発生。

C:\>gem install -r libxml-ruby
Need to update 1 gems from http://gems.rubyforge.org
.
complete
Building native extensions.  This could take a while...
ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)
    ERROR: Failed to build gem native extension.

ruby extconf.rb install -r libxml-ruby
checking for socket() in socket.lib... no
checking for gethostbyname() in nsl.lib... no
checking for atan() in m.lib... yes
checking for inflate() in z.lib... no
checking for inflate() in zlib1.lib... no
 extconf failure: need zlib
*** 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
        --srcdir=.
        --curdir
        --ruby=C:/ruby/bin/ruby
        --with-iconv-dir
        --without-iconv-dir
        --with-iconv-include
        --without-iconv-include=${iconv-dir}/include
        --with-iconv-lib
        --without-iconv-lib=${iconv-dir}/lib
        --with-xml2-dir
        --without-xml2-dir
        --with-xml2-include
        --without-xml2-include=${xml2-dir}/include
        --with-xml2-lib
        --without-xml2-lib=${xml2-dir}/lib
        --with-zlib-dir
        --without-zlib-dir
        --with-zlib-include
        --without-zlib-include=${zlib-dir}/include
        --with-zlib-lib
        --without-zlib-lib=${zlib-dir}/lib
        --with-socketlib
        --without-socketlib
        --with-nsllib
        --without-nsllib
        --with-mlib
        --without-mlib
        --with-zlib
        --without-zlib
        --with-zlib1lib
        --without-zlib1lib


Gem files will remain installed in C:/ruby/lib/ruby/gems/1.8/gems/libxml-ruby-0.
3.8.4 for inspection.
Results logged to C:/ruby/lib/ruby/gems/1.8/gems/libxml-ruby-0.3.8.4/ext/xml/gem
_make.out

いろいろ調べたところ、どーやらlibxml2が入ってないとだめらしい。ので、libxml2のサイトからバイナリダウンロードしてC:/WINDOWS/system32/以下にいれてやり、あらためてgemした…けどだめだった。

なんでやねん！だれかおせーてー｡･ﾟ･(ﾉД`)･ﾟ･｡