Configuring Unreal Build System

UnrealBuildTool reads settings from XML configuration files in the following locations:

* Engine/Programs/NotForLicensees/UnrealBuildTool/BuildConfiguration.xml
* Engine/Saved/UnrealBuildTool/BuildConfiguration.xml
* *User Folder/AppData*/Roaming/Unreal Engine/UnrealBuildTool/BuildConfiguration.xml
* *My Documents*/Unreal Engine/UnrealBuildTool/BuildConfiguration.xml

The default settings are written to Engine/Programs/UnrealBuildTool/BuildConfiguration.xml as a reference. This file is generated whenever UnrealBuildTool runs; any settings you change here will be overwritten.

UnrealBuldTool Configuration Properties


If true, compilation with XGE will stop when an error occurs.

  • Continuing compiling makes subsequent compiles much faster after you fix the odd error.

  • It lets you see compile errors in all files before quitting the build.

  • You can use Ctrl + Break to interrupt a failed build.


If true, debug info is not included when building in Development configuration.

  • Set to false to always include debug info.

  • Including debug info slows down compiling, but gives you line numbers and stack info in Development builds.


Set to true when rebuilding the engine as a whole. This should be disabled when using fast iteration mode.


If true, compile and link times are dramatically decreased. This should be disabled when creating unity builds.

  • Setting to true gives fastest iteration times.

  • If you encounter weird "RPC" or "PDB" link errors, then you should set bUseIncrementalLinking = false in ValidateConfiguration()