Gem update on Windows - is it broken?

Updating sqlite3-ruby
Building native extensions.  This could take a while...
ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)
  ERROR: Failed to build gem native extension.

c:/ruby/bin/ruby.exe extconf.rb update
checking for fdatasync() in rt.lib... no
checking for sqlite3.h... no

nmake
'nmake' is not recognized as an internal or external command,
operable program or batch file.

$ gem -v
1.2.0

$ ruby -v
ruby 1.8.6 (2007-09-24 patchlevel 111) [i386-mswin32]

gem update --system

`gem.bat outdated`.split(/n/).map{|z|z.scan(/^[^[:space:]]+/)}.flatten.each{|z| `gem.bat update #{z}`}

gem install sqlite3-ruby --version '1.2.3'

gem install sqlite3-ruby --platform=mswin32