错误#1：Apple Mach-O链接器错误：链接器命令失败,退出代码为1

ld: file not found: /Users/Linus/Library/Developer/Xcode/DerivedData/MyApp-asdjeshhsetnfxbegcsbcipdreneewgr/Build/Intermediates/MyApp.build/Debug-iphonesimulator/MyApp.build/Objects-normal/x86_64/DownloadsViewController.o
clang: error: linker command Failed with exit code 1 (use -v to see invocation)

我甚至不知道一个.o文件是什么.然而,下载ViewController的快速文件是存在的.

错误#2：同上错误：命令/usr/cin / ditto失败,退出代码1

ditto: can’t get real path for source ‘/Users/Linus/Library/Developer/Xcode/DerivedData/MyApp-asdjeshhsetnfxbbciegrfdpdreneewgr/Build/Intermediates/MyApp.build/Debug-iphonesimulator/MyApp.build/Objects-normal/x86_64/MyApp-Swift.h’
Command /usr/bin/ditto Failed with exit code 1

同时发生错误3次：对于MyApp.swiftdoc,MyApp.swiftmodule和MyApp-Swift.h.

提前致谢！