安装Rails时出现"extconf.rb failed“消息

Question

新手来了。我已经在网站上搜索了其他类似的问题，但仍然无法解决这个问题。我已经安装了Ruby2.0.0和RubyGem 2.0.3，但是当我尝试安装Rails 4.0.0时，我得到了：

    Building native extensions.  This could take a while...
ERROR:  Error installing rails:
    ERROR: Failed to build gem native extension.
    /Users/yuanhunglo/.rvm/rubies/ruby-2.0.0-p0/bin/ruby extconf.rb
*** 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
    --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=/Users/yuanhunglo/.rvm/rubies/ruby-2.0.0-p0/bin/ruby
    --with-atomic_reference-dir
    --without-atomic_reference-dir
    --with-atomic_reference-include
    --without-atomic_reference-include=${atomic_reference-dir}/include
    --with-atomic_reference-lib
    --without-atomic_reference-lib=${atomic_reference-dir}/
/Users/yuanhunglo/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/mkmf.rb:431:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
    from /Users/yuanhunglo/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/mkmf.rb:516:in `try_link0'
    from /Users/yuanhunglo/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/mkmf.rb:814:in `try_run'
    from extconf.rb:22:in `<main>'


Gem files will remain installed in /Users/yuanhunglo/.rvm/gems/ruby-2.0.0-p0/gems/atomic-1.1.10 for inspection.
Results logged to /Users/yuanhunglo/.rvm/gems/ruby-2.0.0-p0/gems/atomic-1.1.10/ext/gem_make.out

我尝试通过以下方式安装Rails

gem install rails --version 4.0.0

我不确定设置是否有问题，或者我是否仍然需要安装某些东西。提前感谢您的帮助。

Answer 1

看起来你在使用OSX。

当你不能编译一些扩展时，就会出现这个错误，在这种情况下，是因为缺少编译器(“你必须先安装开发工具”)。打开应用商店，下载XCode，安装后，点击菜单上的"XCode“，进入Preferences -> Downloads -> Components并下载”命令行工具“。