生成dumpdecrypted.dylib时显示警告ld: warning: directory not found for option ...PrivateFrameworks

环境：Mac Version 11.2.1 , XCode Version 12.4

问题：

生成dumpdecrypted.dylib时显示警告，具体如下：

ld: warning: directory not found for option '-F/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS14.4.sdk/System/Library/PrivateFrameworks'
ld: warning: directory not found for option '-F/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS14.4.sdk/System/Library/PrivateFrameworks'
ld: warning: directory not found for option '-F/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS14.4.sdk/System/Library/PrivateFrameworks'
           

从警告来看，是PrivateFrameworks找不到，进入到该警告路径，发现确实没有PrivateFrameworks，在XCode包中查找，发现PrivateFrameworks存在于

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/
           

解决方案：

把PrivateFrameworks拷贝到

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS14.4.sdk/System/Library/
           

再次执行make命令，生成dumpdecrypted.dylib，发现成功，信息如下

`xcrun --sdk iphoneos --find gcc` -Os  -Wimplicit -isysroot `xcrun --sdk iphoneos --show-sdk-path` -F`xcrun --sdk iphoneos --show-sdk-path`/System/Library/Frameworks -F`xcrun --sdk iphoneos --show-sdk-path`/System/Library/PrivateFrameworks -arch armv7 -arch armv7s -arch arm64 -c -o dumpdecrypted.o dumpdecrypted.c 
`xcrun --sdk iphoneos --find gcc` -Os  -Wimplicit -isysroot `xcrun --sdk iphoneos --show-sdk-path` -F`xcrun --sdk iphoneos --show-sdk-path`/System/Library/Frameworks -F`xcrun --sdk iphoneos --show-sdk-path`/System/Library/PrivateFrameworks -arch armv7 -arch armv7s -arch arm64 -dynamiclib -o dumpdecrypted.dylib dumpdecrypted.o