The BuildTarget to build.
For best results, leave this property unset so that the build uses the target defined in the active BuildProfile. If you do set it, set it to match the active build target.
Building a target that doesn't match the active build target is unreliable. Changing the active build target requires recompiling Editor scripts for the new platform and a domain reload, which can't happen while a build script is running. As a result, build callbacks and platform-dependent code might compile for the wrong platform, and some platforms fail to build at all.
To select the target, set the active build profile first: use the Build Profiles window in the Editor, or the -activeBuildProfile or -buildTarget argument on the command line. For more information, refer to Create a custom build script.
Additional resources: EditorUserBuildSettings.activeBuildTarget