Configuring sourceSets for subprojects not working in root project

I have the following snippet in my root project:

    subprojects {
         sourceSets.main.java.srcDirs += project.ext.generatedSrcDir
         sourceSets.main.resources.srcDirs += "$projectDir/../xsd"
    }

The generate java is getting picked up and the classes added to the jar but the resources are not being added to the jar. However if I put

sourceSets.main.resources.srcDirs += "$projectDir/../xsd"

directly in the subproject’s build.gradle they do get picked up. What is going on here?

Found the problem. It was a spelling mistake should have been xsl