ruby-on-rails -/usr/bin/gcc-4.2 : No such file or directory. 错误。符号链接(symbolic link)修复不起作用

Question

我正在尝试升级我的 rails 3.2.3 应用程序。我已将 gemfile 更新为 gem 'rails', '3.2.11'并运行 bundle update rails但出现以下错误:

    Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

        /Users/Arel/.rvm/rubies/ruby-1.9.3-head/bin/ruby extconf.rb 
creating Makefile

make
compiling generator.c
make: /usr/bin/gcc-4.2: No such file or directory
make: *** [generator.o] Error 1


Gem files will remain installed in /Users/Arel/.rvm/gems/ruby-1.9.3-head/gems/json-1.7.6 for inspection.
Results logged to /Users/Arel/.rvm/gems/ruby-1.9.3-head/gems/json-1.7.6/ext/json/ext/generator/gem_make.out
An error occured while installing json (1.7.6), and Bundler cannot continue.
Make sure that `gem install json -v '1.7.6'` succeeds before bundling.

因此，我尝试了随处可见的解决方案，使用以下命令创建符号链接(symbolic link):
sudo ln -s /usr/bin/gcc /usr/bin/gcc-4.2
但这只是返回错误:
ln: /usr/bin/gcc-4.2: File exists
我不太了解使用终端在 OSX 中导航，所以我在这里有点挣扎。有任何想法吗？

Answer 1

/usr/bin/gcc-4.2可能已经是一个符号链接(symbolic link)，但是一个损坏的链接指向一个不存在的文件。