gem install 時報錯，no such file to load -- zlib

通過gem 安裝mysql庫時，報告

#gem install mysql
ERROR: Loading command: install (LoadError)
no such file to load -- zlib
ERROR: While executing gem ... (NameError)
uninitialized constant Gem::Commands::InstallCommand

解決辦法是：

進入ruby源碼文件夾
安裝ruby自身提供的zlib包
#cd ext/zlib
#ruby ./extconf.rb
#make
#make install

問題解決