It might be obvious for experienced gradle users but for a new user the documentation regarding the usage of gradle.properties files in a multi project build might miss a note when it comes to system properties:
In chapter 14.2, 2nd paragraph is explained that in a multi project build a gradle.properties file can be located in every sub project. In the 4th paragraph is explained that it is possible to set system properties using a gradle.properties file.
When you combine the informations from the two paragraphs the impression evolves that you can set system properties in a sub project gradle.properties file what does not work. A system property can only be set in the “root” gradle.properties. Any attempt to set it in a sub project gradle.properties file is ignored. I suggest to add one sentence to the docu chapter 14.2 fourth paragraph to make this more clear, e.g. “For multi-project builds this must be done in the root gradle.properties file because this information can not be passed to sub projects”.