mac os 10.10 pod install errors

/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby -rubygems /Library/Ruby/Gems/2.0.0/gems/rake-0.9.6/bin/rake RUBYARCHDIR=/Library/Ruby/Gems/2.0.0/extensions/universal-darwin-14/2.0.0/xcodeproj-0.17.0 RUBYLIBDIR=/Library/Ruby/Gems/2.0.0/extensions/universal-darwin-14/2.0.0/xcodeproj-0.17.0/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rbchecking for -std=c99 option to compiler... *** extconf.rb failed ***Could not create Makefile due to some reason, probably lack of necessarylibraries and/or headers.  Check the mkmf.log file for more details.  You mayneed 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=/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/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 /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `block in try_compile'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:502:in `with_werror'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `try_compile'    from extconf.rb:24:in `block in <main>'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:895:in `block in checking_for'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'    from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:894:in `checking_for'    from extconf.rb:23:in `<main>'rake aborted!Command failed with status (1): [/System/Library/Frameworks/Ruby.framework/...]/Library/Ruby/Gems/2.0.0/gems/xcodeproj-0.17.0/ext/xcodeproj/Rakefile:37:in `block in <top (required)>'Tasks: TOP => default => ext(See full trace by running task with --trace)

升级到Mac OS X 10.10 Yosemite，今天用pod添加库的时候发现出现问题了。

解决方式：

首先安装Xcode6 的 Command Line Tools，在开发者中心下载接下来按照下面步骤操作：打开 Xcode 6打开 Preferences选择 Locations 选项卡将 Command Line Tools 选择为 Xcode 6.0卸载 cocoapods$ sudo gem uninstall cocoapods安装 xcodeproj$ sudo gem install xcodeproj再安装 cocoapods$ sudo gem install cocoapods最后运行 pod --version 就看到Pod正常了。