ruby on railsインストールでエラー

ruby on railsをインストールをしようと思い、rubyをインストールして

gem install rails

をじっこうしたところ下記がでました　助けてください

Temporarily enhancing PATH for MSYS/MINGW...
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.

C:/Ruby24-x64/bin/ruby.exe extconf.rb
checking for unistd.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.

Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=C:/Ruby24-x64/bin/$(RUBY_BASE_NAME)
C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:457:in `try_do': The compiler failed to gen
erate an executable file. (RuntimeError)
You have to install development tools first.
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:588:in `try_cpp'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:1095:in `block in have_header'

from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:945:in `block in checking_for'

from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:351:in `block (2 levels) in po
stpone'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:321:in `open'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:351:in `block in postpone'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:321:in `open'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:347:in `postpone'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:944:in `checking_for'
from C:/Ruby24-x64/lib/ruby/2.4.0/mkmf.rb:1094:in `have_header'
from extconf.rb:5:in `<main>'


Gem files will remain installed in C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/nio4r-
2.1.0 for inspection.
Results logged to C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/nio4r-2.1.0/ext/nio4r/g
em_make.out

No.1 ベストアンサー 回答者： goold-man 回答日時： 2017/07/17 03:18

＞MSYS

MSYS2？

MSYS/Rubyをアンインストール→MSYSをインストール→Ruby 2.4をインストール→MSYS and MINGW development toolchain の実行→gemのインストール→railsのインストール

http://qiita.com/KTakata/items/1f30b8571764f7801 …