錯誤內容如下：
mattias@mattias-Desktop:~$ gem install rails
Fetching: thread_safe-0.3.5.gem (100%)
Successfully installed thread_safe-0.3.5
Fetching: minitest-5.8.1.gem (100%)
Successfully installed minitest-5.8.1
Fetching: tzinfo-1.2.2.gem (100%)
Successfully installed tzinfo-1.2.2
Fetching: i18n-0.7.0.gem (100%)
Successfully installed i18n-0.7.0
Fetching: activesupport-4.2.4.gem (100%)
Successfully installed activesupport-4.2.4
Fetching: rails-deprecated_sanitizer-1.0.3.gem (100%)
Successfully installed rails-deprecated_sanitizer-1.0.3
Fetching: mini_portile-0.6.2.gem (100%)
Successfully installed mini_portile-0.6.2
Fetching: nokogiri-1.6.6.2.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
/home/mattias/.rvm/rubies/ruby-2.2.3/bin/ruby -r ./siteconf20150930-14059-do0e7v.rb extconf.rb
checking if the C compiler accepts ... *** 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=/home/mattias/.rvm/rubies/ruby-2.2.3/bin/$(RUBY_BASE_NAME)
--help
--clean
/home/mattias/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /home/mattias/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/mkmf.rb:571:in `block in try_compile'
from /home/mattias/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/mkmf.rb:522:in `with_werror'
from /home/mattias/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/mkmf.rb:571:in `try_compile'
from extconf.rb:80:in `nokogiri_try_compile'
from extconf.rb:87:in `block in add_cflags'
from /home/mattias/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/mkmf.rb:619:in `with_cflags'
from extconf.rb:86:in `add_cflags'
from extconf.rb:337:in `'
extconf failed, exit code 1
Gem files will remain installed in /home/mattias/.rvm/gems/ruby-2.2.3/gems/nokogiri-1.6.6.2 for inspection.
Results logged to /home/mattias/.rvm/gems/ruby-2.2.3/extensions/x86_64-linux/2.2.0/nokogiri-1.6.6.2/gem_make.out 其中有一句寫到 "Check the mkmf.log file for more details."，那就來找出這支檔案看一下到底哪裡出問題了吧！
