Fatal error by running IntegrationTest: missing dependency module mailmute.

Problem/Motivation

I've testing something else, ran Drupal\inmail\Tests\IntegrationTest::testBounceFlow on a clean branch and got fatal error on the parent::setUp() (line 36):

Unable to install modules: module 'inmail_mailmute' is missing its dependency module mailmute.

Drupal\Core\Config\Schema\SchemaIncompleteException: No schema for inmail.settings in Drupal\Core\Config\Testing\ConfigSchemaChecker->onConfigSave() (line 86 of /usr/local/var/www/d8.dev/www/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php).

Drupal\Core\Config\Testing\ConfigSchemaChecker->onConfigSave(Object, 'config.save', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('config.save', Object) (Line: 227)
Drupal\Core\Config\Config->save() (Line: 45)
Drupal\inmail\Tests\IntegrationTest->setUp() (Line: 1049)
Drupal\simpletest\TestBase->run(Array) (Line: 752)
simpletest_script_run_one_test('3', 'Drupal\inmail\Tests\IntegrationTest::testBounceFlow') (Line: 66)

Asked a colleague to run the same test, but it works for him...
Does anyone knows how to fix it ?

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes