gradle openapi generator doesn't work for selective generation

When we run gradle openapi generator tasks, part of the generated output has an infrastructure folder with all of the shared/common files required for the client to build.

When I start specifying the apis and models that I want generated, then this infrastructure folder is no longer created, so nothing builds!!

What am I doing wrong?

task buildMyClient(type: org.openapitools.generator.gradle.plugin.tasks.GenerateTask){
    generatorName = "kotlin"
    inputSpec = "$rootDir/openapi/specs/myservice.yaml".toString()
    outputDir = "$buildDir/generated".toString()
    apiPackage = "com.mycompany.myservice"
    packageName = "com.mycompany.myservice"
    modelPackage = "com.mycompany.myservice.model"
    globalProperties = [
        apis: "MyController",
        models: "MyApiRequest,MyApiResponse,EmbeddedApiResponse"]
    configOptions = [
            "enumPropertyNaming": "UPPERCASE"
    ]
}

Here are the docs on the gradle plugin: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator-gradle-plugin/README.adoc

Here are the docs on global properties: https://openapi-generator.tech/docs/globals/

Seems that I might have to specify all supporting files? How do I do that? There isn't some way to use the default?