构建iOS项目得到了架构i386错误的重复符号

Question

我在我的项目中使用了paho MQTT库。

当我在模拟器上构建项目时，我遇到了以下错误。

duplicate symbol _client_version_eye in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTClient.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTAsync.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTAsync.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTProtocolClient.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/Socket.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPersistence.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/Thread.o duplicate symbol _Log_levels in: /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTPacket.o /Users/xieweizhi/Library/Developer/Xcode/DerivedData/mgiosapp-bctgnqpjhalyqageaduowfwrsrkh/Build/Intermediates/mgiosapp.build/Debug-iphonesimulator/mgiosapp.build/Objects-normal/i386/MQTTProtocolOut.o ld: 25 duplicate symbols for architecture i386 clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

试试吧......

将一个文件的内容复制并粘贴到另一个文件时，可能会发生错误，该文件的接口名称为两个具有相同接口名称的类。

在您的代码中，您有两个具有相同接口名称的不同文件。

问题很可能是由于包含标题时的拼写错误。

检查是否包含头文件（.h）而不是实现文件（.m）。

同时清理项目和构建文件夹有时它也会解决此错误

同时删除派生数据。

Answer 2

MQTTClient.c和MQTTAsync.c不应包含在同一项目中。它们用于构建不同的库。确定是否需要阻止或异步行为并使用该文件。