* Project extensions and conventions (such as `sourceSets`), and extensions on them
* Extensions on the `dependencies` and `repositories` containers, and extensions on them
* Elements in the `tasks` and `configurations` containers
* Elements in <<kotdsl:containers,project-extension containers>> (for example the source sets contributed by the Java Plugin that are added to the `sourceSets` container)

For the main project settings script:

    }

    void "ignores extra artifacts added to configurations"() {
        given:
        createBuildScripts("""
            task extraJar(type: Jar) {
                from sourceSets.main.allJava
                archiveBaseName = "publishTest-extra"
            }

            artifacts {
                implementation extraJar
                archives extraJar

----
plugins {
    id("java-library")
}

sourceSets {
    create("feature")
}

java {
    registerFeature("feature") {
        usingSourceSet(sourceSets["feature"])
    }
}
----
======
[.multi-language-sample]
======
.build.gradle
[source,groovy]
----
plugins {
    id("java-library")
}

sourceSets {
    feature
}

java {

```groovy
sourceSets {
    main {
        groovy {
            // ...
        }
    }
}
```

However, the return type of the groovy block has changed to the extension type.
This means that the following snippet no longer works in Gradle 7.1:

```groovy
 sourceSets {
     main {
         GroovySourceSet sourceSet = groovy {
             // ...

                canBeResolved = false
                assert canBeConsumed
            }

            task redJar(type: Jar) {
                archiveClassifier = 'red'
                from(sourceSets.main.output)
            }

            artifacts {
                custom redJar
            }
        """.stripIndent()

        and:
        file("src/main/java/Hello.java") << """

Method <org.gradle.api.tasks.SourceSet.java(groovy.lang.Closure)> has arguments/return type groovy.lang.Closure that is not Gradle public API or primitive or built-in JDK classes or Kotlin classes in (SourceSet.java:0)

The example also does the following, not all of which you may need for your specific integration tests:

 * Adds the production classes from the `main` source set to the compilation and runtime classpaths of the integration tests — `sourceSets.main.output` is a <<working_with_files.adoc#sec:file_collections,file collection>> of all the directories containing compiled production classes and resources

Here's an example of a problematic task type referencing a `SourceSet`:

====
include::sample[dir="snippets/configurationCache/disallowedTypes/kotlin",files="build.gradle.kts[tags=task-type]"]
include::sample[dir="snippets/configurationCache/disallowedTypes/groovy",files="build.gradle[tags=task-type]"]
====
<1> this will be reported as a problem because referencing `SourceSet` is not allowed

The following is how it should be done instead: