succeeds 'printFilesWithConfigurationInput'

        then:
        outputContains('[dep1-1.0.jar, dep2-1.0.jar]')

        when:

            .expectLegacyDeprecationWarning("Mutating the hierarchy of configuration ':apiElements' after it has been resolved or consumed. This behavior has been deprecated. This will fail with an error in Gradle 9.0. After a...

        executer.expectDocumentedDeprecationWarning("Mutating the dependency attributes of configuration ':parent' after it has been resolved or consumed. This behavior has been deprecated. This will fail with an error in Gradle...

        run "checkDeps"

        then:
        resolve.expectGraph {
            root(":", ":test:") {
                module("org:default-dependency:1.0")
            }
        }

                .willBecomeAnErrorInGradle9()
                .withUpgradeGuideSection(8, "mutate_configuration_after_locking")
                .nagUser();
            return true;
        }
        return false;
    }

    private void preventIllegalParentMutation(MutationType type) {

(which was never API) has been moved to new internal packages (`org.gradle.internal.*`).

[[changes_8.8]]
== Upgrading from 8.7 and earlier

=== Deprecations

[[mutate_configuration_after_locking]]
==== Deprecate mutating configuration after observation

To ensure the accuracy of dependency resolution, Gradle checks that Configurations are not mutated after they have been used as part of a dependency graph.