Platform Linux is not a valid platform to build. Check that the SDK is installed properly 解决办法
问题：
在CentOS7上源码编译4.27版本时，生成工程时报以下错误：
WARNING: Exception while generating include data for UE4Editor: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for BenchmarkTool: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for BlankProgram: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for BuildPatchTool: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for ChaosVisualDebugger: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for CrashReportClient: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for CrashReportClientEditor: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for DatasmithUE4ArchiCAD: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for DatasmithSDK: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for HeadlessChaos: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for HeadlessChaosPerf: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for LiveCodingConsole: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for ShaderCompileWorker: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for SlateViewer: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for SwitchboardListener: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for TestPAL: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for TextureShareSDK: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealCEFSubProcess: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealFileServer: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealFrontend: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealHeaderTool: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealInsights: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealLightmass: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealMultiUserServer: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealPak: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealRecoverySvc: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for UnrealVersionSelector: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
WARNING: Exception while generating include data for BootstrapPackagedGame: Platform Linux is not a valid platform to build. Check that the SDK is installed properly.
原因：
Engine/Extras/ThirdPartyNotUE/SDKs/HostLinux/Linux_x64 目录下的 v19_clang-11.0.1-centos7 下载不全
解决办法：
4.27是用 v19_clang-11.0.1版本，下载对应的clang版本，替换掉 Engine/Extras/ThirdPartyNotUE/SDKs/HostLinux/Linux_x64/v19_clang-11.0.1-centos7 即可。
下载地址：https://docs.unrealengine.com/4.27/en-US/SharingAndReleasing/Linux/GettingStarted
