我在Windows上将ruby从2.1 ..升级到2.4.1，并安装了msys2工具包。
然而每次安装一个调用Makefile的gem我得到一个ERROR: Failed to build gem native extension
c:\>gem install oj
Temporarily enhancing PATH for MSYS/MINGW...
Building native extensions. This could take a while...
ERROR: Error installing oj
ERROR: Failed to build gem native extension.
current directory: C:/tools/ruby24/lib/ruby/gems/2.4.0/gems/oj-3.1.3/ext/oj
C:/tools/ruby24/bin/ruby.exe -r ./siteconf20170616-1724-1fw22px.rb extconf.rb
Creating Makefile for ruby version 2.4.1 on x64-mingw32
creating Makefile
extconf.rb:68:in ``': No such file or directory - make clean
(Errno::ENOENT)
from extconf.rb:68:in `<main>'
extconf failed, exit code 1
在安装其他一些宝石时，我也会遇到类似的错误，例如json