[Custom tokens] - Entity clone does not work properly [#2877626]

With the release of version 8.x-1.0-alpha1 of Custom Tokens the tokens are entities now (see 2862994) So I've tried to clone an entity, but I get the following exception:

Drupal\Core\Entity\EntityStorageException: SQLSTATE[HY000]: General error: 1364 Field 'machine_name' doesn't have a default value: INSERT INTO {token_custom} (type, name, description, content, format, is_new) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5); Array ( [:db_insert_placeholder_0] => custom [:db_insert_placeholder_1] => test - Cloned [:db_insert_placeholder_2] => test [:db_insert_placeholder_3] => <p>test</p> [:db_insert_placeholder_4] => basic_html [:db_insert_placeholder_5] => ) in Drupal\Core\Entity\Sql\SqlContentEntityStorage->save() (line 777 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Database\Statement->execute(Array, Array) (Line: 624)
Drupal\Core\Database\Connection->query('INSERT INTO {token_custom} (type, name, description, content, format, is_new) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5)', Array, Array) (Line: 87)
Drupal\Core\Database\Driver\mysql\Connection->query('INSERT INTO {token_custom} (type, name, description, content, format, is_new) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5)', Array, Array) (Line: 32)
Drupal\Core\Database\Driver\mysql\Insert->execute() (Line: 850)
Drupal\Core\Entity\Sql\SqlContentEntityStorage->doSaveFieldItems(Object) (Line: 263)
Drupal\Core\Entity\ContentEntityStorageBase->doSave(NULL, Object) (Line: 392)
Drupal\Core\Entity\EntityStorageBase->save(Object) (Line: 768)
Drupal\Core\Entity\Sql\SqlContentEntityStorage->save(Object) (Line: 364)
Drupal\Core\Entity\Entity->save() (Line: 62)
Drupal\entity_clone\EntityClone\Content\ContentEntityCloneBase->cloneEntity(Object, Object, Array) (Line: 140)
Drupal\entity_clone\Form\EntityCloneForm->submitForm(Array, Object)
call_user_func_array(Array, Array) (Line: 111)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object) (Line: 51)
Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object) (Line: 585)
Drupal\Core\Form\FormBuilder->processForm('entity_clone_form', Array, Object) (Line: 314)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 74)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 574)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
call_user_func_array(Object, Array) (Line: 144)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 64)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)