Change record status: 
Project: 
Introduced in branch: 
8.6.x
Introduced in version: 
8.6.0
Description: 

All tests that extend from \Drupal\FunctionalTests\Update\UpdatePathTestBase must be in the legacy group. This is because update function (by their nature) call deprecated code paths.

For example:

/**
 * Runs UpdatePathTestBaseTest with a dump filled with content.
 *
 * @group Update
 * @group legacy
 */
class UpdatePathTestBaseFilledTest extends UpdatePathTestBaseTest {

For more on deprecated code testing in Drupal 8, see the https://www.drupal.org/node/2811561 change record.

Impacts: 
Module developers