TYPO3 Core

lolli@apoc /var/www/local/cms/Web $ ./bin/phpunit -c vendor/typo3/testing-framework/Resources/Core/Build/UnitTests.xml typo3/sysext/form/Tests/Unit/Service/TranslationServiceTest.php
PHPUnit 7.1.5 by Sebastian Bergmann and contributors.

.....F............................                                34 / 34 (100%)

Time: 636 ms, Memory: 20,00MB

There was 1 failure:

1) TYPO3\CMS\Form\Tests\Unit\Service\TranslationServiceTest::translateReturnsExistingLanguageKeyForLanguageIfExtPathLanguageKeyIsRequested
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'FORM DE'
+'FORM EN'

/var/www/local/cms/Web/typo3/sysext/form/Tests/Unit/Service/TranslationServiceTest.php:189
/var/www/local/cms/Web/vendor/phpunit/phpunit/phpunit:53

FAILURES!
Tests: 34, Assertions: 106, Failures: 1.

lolli@apoc /var/www/local/cms/Web $ mv typo3conf/l10n/de/form .

lolli@apoc /var/www/local/cms/Web $ ./bin/phpunit -c vendor/typo3/testing-framework/Resources/Core/Build/UnitTests.xml typo3/sysext/form/Tests/Unit/Service/TranslationServiceTest.php
PHPUnit 7.1.5 by Sebastian Bergmann and contributors.

..................................                                34 / 34 (100%)

Time: 636 ms, Memory: 20,00MB

OK (34 tests, 106 assertions)

Incomplete mocking or something?