string projectTarget = proj.ProjectGuid();

​

Relying on the [PostProcessBuild] attribute instead setting up cloud build to call a specified postprocess seems to not work. This method exists in my editor folder, in a static build settings class. ​

No trailing parenthesis, and it can't have the same name as your Pre-Export method! This method must accept a string parameter, which will receive the path to the exported Unity player (or Xcode project in the case of iOS).​