无法安装Rails extconf.rb失败

Question

我是Ruby on Rails的新手，当我安装它时，我得到了下面的错误。

请注意，我已经安装了最新的Xcode和命令行工具，并且我使用的是OSX 10.8.4。我也安装了Ruby 2.0.0。

-bash-3.2$ sudo gem install rails
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
ERROR: Failed to build gem native extension.

/Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/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
--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=/Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/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/WillieTran/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:434:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:519:in `try_link0'
from /Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/mkmf.rb:817:in `try_run'
from extconf.rb:24:in `<main>'


Gem files will remain installed in /Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/atomic-1.1.12 for inspection.
Results logged to /Users/WillieTran/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/gems/2.0.0/gems/atomic-1.1.12/ext/gem_make.out

Answer 1

我也遇到过类似的问题，可以通过安装命令行工具来解决：

xcode-select --install

Answer 2

符号链接没有为我解决这个问题。我先输入rvm uninstall ruby-2.0.0，然后输入rvm requirements，卸载了之前使用rvm安装的ruby。这个命令发现我还需要一些其他的东西，比如gcc46。奇怪的是，尽管我已经安装了xcode命令行工具，而且我的系统上肯定安装了gcc，但为什么还需要gcc编译器。

因此，如果常用的方法都不起作用，那就试试rvm requirements吧！

Answer 3

我猜this question也有同样的问题。

再次尝试sudo ln -s /usr/bin/{llvm-,}gcc-4.2和gem install rails。

顺便说一下，你在你自己的主目录中，你不需要使用sudo。