安装时出现一些错误yajl-ruby

Question

当我跑步时：

sudo gem install yajl-ruby

我看到了错误：

Building native extensions.  This could take a while...
ERROR:  Error installing yajl-ruby:
        ERROR: Failed to build gem native extension.

/usr/bin/ruby extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib/ruby/ruby.h


Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/yajl-ruby-1.2.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/yajl-ruby-1.2.1/ext/yajl/gem_make.out

我已经安装了yum install ruby​​ ruby​​gems ruby​​-devel，但仍然有这个问题。