private final ImmutableList<String> rebuildReasons;
    private final ExecutionStateChanges executionStateChanges;

    public IncrementalChangesContext(
        ValidationFinishedContext parent,
        ImmutableList<String> rebuildReasons,
        @Nullable ExecutionStateChanges executionStateChanges
    ) {
        super(parent);
        this.rebuildReasons = rebuildReasons;

        1 * delegate.execute(work, _ as IncrementalChangesContext) >> { UnitOfWork work, IncrementalChangesContext delegateContext ->
            def changes = delegateContext.changes.get()
            assert delegateContext.rebuildReasons == ImmutableList.of("Forced rebuild.")
            assert !changes.createInputChanges().incremental
            return delegateResult
        }
        _ * context.nonIncrementalReason >> Optional.of("Forced rebuild.")

            inputFilePropertyChanges,
            nonIncrementalInputFileChanges
        ));
        ImmutableList<String> rebuildReasons = collectChanges(rebuildTriggeringChanges);

        if (!rebuildReasons.isEmpty()) {
            return ExecutionStateChanges.nonIncremental(
                rebuildReasons,
                thisExecution,
                incrementalInputProperties
            );
        } else {

        then:
        result.execution.get().outcome == UP_TO_DATE
        !result.executionReasons.present

        _ * context.changes >> Optional.of(changes)
        _ * context.rebuildReasons >> ImmutableList.of()
        _ * context.previousExecutionState >> Optional.of(Stub(PreviousExecutionState) {
            getOutputFilesProducedByWork() >> ImmutableSortedMap.of()

    private final Optional<String> rebuildReason;
    private final boolean taskHistoryMaintained;
    private final boolean allowedToUseCachedResults;

    DefaultTaskExecutionMode(@Nullable String rebuildReason, boolean taskHistoryMaintained, boolean allowedToUseCachedResults) {
        this.rebuildReason = Optional.ofNullable(rebuildReason);
        this.taskHistoryMaintained = taskHistoryMaintained;

            .orElseGet(() -> {
                ImmutableList<String> rebuildReason = context.getNonIncrementalReason()
                    .map(ImmutableList::of)
                    .orElse(UNTRACKED);
                return new IncrementalChangesContext(context, rebuildReason, null);
            });

        return delegate.execute(work, delegateContext);
    }

    @Nonnull