這兩天由於同事都相繼更新了系統和XCode10導致有些沒更新系統和XCode的同事代碼遇到一些問題，下面列出我遇見的幾個問題：
問題一、Build input file cannot be found:'/Users/xxxxx/lib/DataLib/build/Debug-iphoneos/libDataLib.a'
報錯圖片如下：
問題二、Multiple commands produce
問題詳情
:-1: Multiple commands produce '/Users/mac/Library/Developer/Xcode/DerivedData/NewAirCloud-aleqredxbgkylvbkglvqefavfggd/Build/Products/Debug-iphoneos/NewAirCloud.app/Info.plist':
1) Target 'NewAirCloud' (project 'NewAirCloud') has copy command from '/Users/mac/Desktop/NewAirCloud-iOS/NewAirCloud/NewAirCloud/External/BaiDuAR/Vendors/SSZipArchive/Info.plist' to '/Users/mac/Library/Developer/Xcode/DerivedData/NewAirCloud-aleqredxbgkylvbkglvqefavfggd/Build/Products/Debug-iphoneos/NewAirCloud.app/Info.plist'
2) Target 'NewAirCloud' (project 'NewAirCloud') has process command with output '/Users/mac/Library/Developer/Xcode/DerivedData/NewAirCloud-aleqredxbgkylvbkglvqefavfggd/Build/Products/Debug-iphoneos/NewAirCloud.app/Info.plist'
問題截圖如下：
錯誤原因：
原因是XCode10更改默認的編譯系統如下圖：
問題一、二、解決辦法：
1.點擊File --> Project Setting --> Build System 選擇Legacy Build System -->Done
2.command + shift +k：清理緩存即可編譯成功
問題三、ld: library not found for -lstdc++.6.0.9
問題截圖：
問題原因：
Xcode 10 中移除了 “-libstdc++.6.0.9” 等一些過期很久的庫
解決辦法：
1.移除-libstdc++.6.0.9
TARGETS --> Build Phases -->Link Binary With Libraries 找到libstdc++.6.0.9選中點擊➖圖標移除
2.需要在舊版Xcode 9 中查找到“-lstdc++.6.0.9”庫之後，複製一份放入Xcode 10 lib庫中。
具體操作連接:https://www.jianshu.com/p/3e29e9d897c8
問題四："OBJC_CLASS$_CNContactStore", referenced from:objc-class-ref in iflyMSC(IFlyContact.o)
"_OBJC_CLASS_$_CNContactStore", referenced from:
objc-class-ref in iflyMSC(IFlyContact.o)
"_OBJC_CLASS_$_CNContactFetchRequest", referenced from:
objc-class-ref in iflyMSC(IFlyContact.o)
"_CNContactGivenNameKey", referenced from:
-[IFlyContact fetchContactWithContactStore:] in iflyMSC(IFlyContact.o)
"_CNContactFamilyNameKey", referenced from:
-[IFlyContact fetchContactWithContactStore:] in iflyMSC(IFlyContact.o)
問題截圖：
問題原因：
科大訊飛sdk需要添加以下四個依賴庫，升級Xcode10後莫名找不到這些依賴庫
解決辦法：
添加相應依賴：TARGETS --> Build Phases -->Link Binary With Libraries點擊➕號,搜索相應framework，點擊add
