openSUSE 安装compass,mkmf.rb can't find,checking for ffi.h...extconf.rb failed

安装compass时，提示

Fetching: sass-3.4..gem (%)
Successfully installed sass-3.4.
Fetching: ffi-1.9..gem (%)
Building native extensions.  This could take a while...
ERROR:  Error installing compass:
    ERROR: Failed to build gem native extension.

    current directory: /usr/lib64/ruby/gems/2.1./gems/ffi-1.9./ext/ffi_c
/usr/bin/ruby.ruby2. -r ./siteconf20170501--33n3uw.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/lib64/ruby/include/ruby.h

extconf failed, exit code 

Gem files will remain installed in /usr/lib64/ruby/gems/2.1./gems/ffi-1.9. for inspection.
Results logged to /usr/lib64/ruby/gems/2.1./extensions/x86_64-linux/2.1./ffi-1.9./gem_make.out

找资料有说明是缺少mkmf,而mkmf是存在于ruby dev开发包中的，需要安装 ruby1.9.1-dev版本，可是笔者的电脑中ruby的版本是:ruby 2.1.9p490 (2016-03-30 revision 54437) [x86_64-linux-gnu]

可以通过zypper search命令查看相关的ruby安装包

运行: zypper search ruby*

会列出和ruby相关的软件包，在列表中有:

i | ruby2.                                                 | An In-> | 软件包
  | ruby2.                                                 | An In-> | 源代码包
  | ruby2.-devel                                           | Devel-> | 软件包  

-dev和-devel 后缀应该都属于开发包,所以笔者运行了: zypper in ruby2.1-devel 

运行的结果是:新安装ruby2.1-devel 和升级libruby2_1-2_1 ruby2.1 ruby2.1-stdlib 3个软件包

再次尝试运行: gem install compass,提示

ERROR:  Error installing compass:
    ERROR: Failed to build gem native extension.

    current directory: /usr/lib64/ruby/gems/2.1./gems/ffi-1.9./ext/ffi_c
/usr/bin/ruby.ruby2. -r ./siteconf20170501--1fry11r.rb extconf.rb
checking for ffi.h... *** 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.

这提示的是缺少 ffi

在上面执行的:zypper serch ruby* 命令的搜索结果中有:

  | ruby2.-rubygem-fastercsv-testsuite                     | Test -> | 软件包
  | ruby2.-rubygem-ffi                                     | Ruby -> | 软件包
  | ruby2.-rubygem-ffi-doc                                 | RDoc -> | 软件包

运行: zypper in ruby2.1-rubygem-ffi

最后执行: gem install compass之后，安装成功，暂时还不能直接运行compass命令，因为执行时，提示

If 'compass' is not a typo you can use command-not-found to lookup the package that contains it, like this:
    cnf compass

参考资料:

1. zypper命令使用示例
2. linux下各种*-dev或*-devel包的作用
3. 安装compass时出现ERROR: Failed to build gem native extension...... -- mkmf (Load Error)解决办法