報(bào)錯(cuò)描述： podfile升級(jí)之后到最新版本，pod里的內(nèi)容必須明確指出所用第三方庫(kù)的target，否則會(huì)出現(xiàn)The dependency `` is not used in any concrete target這樣的錯(cuò)誤。

解決方法：
以下從三個(gè)步驟陳述：
1. Podfile升級(jí)
查看pod版本：
pod --version

pod 升級(jí)（此時(shí)是升級(jí)到1.0.0.beta.2版本）：
sudo gem install cocoapods --pre

2. 錯(cuò)誤內(nèi)容：
我的Podfile的內(nèi)容是：
platform :ios, ‘7.0‘pod ‘ReactiveCocoa‘, ‘2.1.8‘pod ‘objectiveflickr‘, ‘2.0.4‘pod ‘LinqToObjectiveC‘, ‘2.0.0‘pod ‘SDWebImage‘, ‘3.6‘

pod install后出現(xiàn)錯(cuò)誤The dependency `` is not used in any concrete target
pod install/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/universal-darwin14/rbconfig.rb:213: warning: Insecure world writable dir /Applications/Cocos/tools/ant/bin in PATH, mode 040777Re-creating CocoaPods due to major version update.Updating local specs repositoriesAnalyzing dependencies[!] The dependency ReactiveCocoa (= 2.1.8) is not used in any concrete target.The dependency objectiveflickr (= 2.0.4) is not used in any concrete target.The dependency LinqToObjectiveC (= 2.0.0) is not used in any concrete target.The dependency SDWebImage (= 3.6) is not used in any concrete target.

3. 修改方法：
Podfile內(nèi)容更改：

platform :ios, ‘7.0‘

target "RWTFlickrSearch" do

pod ‘ReactiveCocoa‘, ‘2.1.8‘
pod ‘objectiveflickr‘, ‘2.0.4‘
pod ‘LinqToObjectiveC‘, ‘2.0.0‘
pod ‘SDWebImage‘, ‘3.6‘

end

這樣再運(yùn)行pod install，就會(huì)成功了。