1醒串、升級(jí)Xcode到Version 10.1(10A255)后，運(yùn)行已有項(xiàng)目宠叼，報(bào)如下錯(cuò)誤：
error: Multiple commands produce '/Users/galahad/Library/Developer/Xcode/DerivedData/yoowei-drnrntneloepunakcqbcdycudqeh/Build/Products/Debug-iphoneos/yoowei.app':
1) Target 'yoowei' has create directory command with output '/Users/galahad/Library/Developer/Xcode/DerivedData/yoowei-drnrntneloepunakcqbcdycudqeh/Build/Products/Debug-iphoneos/yoowei.app'
2) That command depends on command in Target 'yoowei': script phase “[CP] Copy Pods Resources”
原因：Xcode 10 默認(rèn)使用的build system是New build system先巴，與Xcode9不同導(dǎo)致。
解決：2種方法
1）第一種方法 不修改build system?
根據(jù)error 日志冒冬，script phase “[CP] Copy Pods Resources”伸蚯，而且與output有關(guān)，應(yīng)該是使用了cocoapods導(dǎo)致的简烤，嘗試刪除該項(xiàng)目target-Copy Pods Resources-Output Files剂邮，成功解決問(wèn)題。選中項(xiàng)目target -> Build phase -> Copy Pods Resources -> Output Files -> 移除${TARGET_BUILD_DIR}/${UNLOCALIZED_RESOURCES_FOLDER_PATH}? 然后重新編譯横侦，OK 挥萌。
用這種方式緊接著會(huì)有下面的錯(cuò)誤：
error: Cycle in dependencies between targets 'yooweiExtension' and 'yoowei'; building could produce unreliable results.
Cycle path:?yooweiExtension →?yoowei→?yooweiExtension
Cycle details:
→ Target 'yooweiExtension': CodeSign /Users/galahad/Library/Developer/Xcode/DerivedData/yoowei-drnrntneloepunakcqbcdycudqeh/Build/Products/Debug-iphoneos/yooweiExtension.appex
○ Target 'yooweiExtension': ProcessProductPackaging? /Users/galahad/Library/Developer/Xcode/DerivedData/yoowei-drnrntneloepunakcqbcdycudqeh/Build/Intermediates.noindex/yoowei.build/Debug-iphoneos/yooweiExtension.build/yooweiExtension.appex.xcent
○ Target 'yooweiExtension' has target dependency on Target 'yoowei'
→ Target 'yoowei' has target dependency on Target 'yooweiExtension'
○ That command depends on command in Target 'yooweiExtension': script phase “[CP] Check Pods Manifest.lock”
對(duì)應(yīng)的解決方案：選中項(xiàng)目target -> Build phase ->?Target Dependencies ?去掉相互的依賴即可
2）第二種方法 修改build system （個(gè)人感覺(jué)這種方式較好，不會(huì)每個(gè)項(xiàng)目搞一遍）
在Xcode菜單欄 -> File -> Workspace Setting枉侧，將build system修改為legacy build system引瀑，然后clean后編譯。
2榨馁、典型問(wèn)題
ld: library not found for -lstdc++.6.0.9
clang: error: linker command failed with exit code 1 (use -v to see invocation)
解決方案：（我一般升級(jí)xcode 之前都會(huì)將lib 給備份一份憨栽。具體路徑是：/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib ）
1、提前在xcode 9中 根據(jù)路徑 ??/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib 找到?libstdc++.6.0.9.tbd ?備份
2、復(fù)制剛才的libstdc++.6.0.9.tbd 文件屑柔，手動(dòng)添加到 升級(jí)后的xcode 10 ?/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib 文件夾中屡萤，運(yùn)行即可。
來(lái)源：http://www.cnblogs.com/richard-youth/p/9777023.html
