我正在尝试在cloud9中遵循本教程。输入后，$rails new myproject我在尝试 $bundle install. 部分错误读取
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
checking for gzdopen() in -lz... no
zlib is missing; necessary for building libxml2
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Make sure that `gem install nokogiri -v '1.6.8.1'` succeeds before bundling.
尝试使用安装$ gem install nokogiri -v 1.6.8.1但得到extconf failed, exit code 1
有没有办法安装 nokogirir 才能$bundle install成功？另外，如何在 cloud9 IDE 中打开 mkmf.log 文件？我试过c9 mkmf.log了，但没有用。