c-knof · Nov 5, 2026 · Nov 5, 2026
diff --git a/components/ILIAS/Language/tests/AdminGuiReadsValuesFromMigratedFileTest.php b/components/ILIAS/Language/tests/AdminGuiReadsValuesFromMigratedFileTest.php
@@ -39,6 +39,8 @@
 #[PreserveGlobalState(false)]
 class AdminGuiReadsValuesFromMigratedFileTest extends ilLanguageBaseTestCase
 {
+    use CapturesErrorLog;
+
     private ?string $fixture_directory = null;
     /** True if this test defined CLIENT_DATA_DIR itself; tearDown() removes only such a root. */
     private bool $created_client_data_dir_root = false;
@@ -538,10 +540,10 @@ public function testWithoutDirectoryManagerOnlyTheRowsOfModulesOfNoComponentAreS
             ['module' => 'rep_robj_xtst', 'identifier' => 'hello', 'value' => 'Welt'],
         ]);
 
-        $this->expectOutputRegex('/Without the language file directories the values of module "poll" are not shown/');
         $values = ilObjLanguageExt::_getValues('de');
 
         $this->assertSame(['rep_robj_xtst#:#hello' => 'Welt'], $values);
+        $this->assertLoggedErrorMatches('/Without the language file directories the values of module "poll" are not shown/');
     }
 
     /** A shipped `.po` that cannot be read: the module is missing (reported), its lng_data rows are not shown instead. */
@@ -558,8 +560,8 @@ public function testAnUnreadableShippedPoHidesTheModuleAndNeverShowsItsLngDataRo
             ['module' => 'rep_robj_xtst', 'identifier' => 'hello', 'value' => 'Welt'],
         ]);
 
-        $this->expectOutputRegex('/The language file of module "mtest" for "de" cannot be read, its values are not shown/');
         $this->assertSame(['rep_robj_xtst#:#hello' => 'Welt'], ilObjLanguageExt::_getValues('de'));
+        $this->assertLoggedErrorMatches('/The language file of module "mtest" for "de" cannot be read, its values are not shown/');
     }
 
     public function testGetModulesIncludesAMigratedModuleEvenWithoutAnyLngDataRow(): void

diff --git a/components/ILIAS/Language/tests/CapturesErrorLog.php b/components/ILIAS/Language/tests/CapturesErrorLog.php
@@ -0,0 +1,80 @@
+<?php
+
+/**
+ * This file is part of ILIAS, a powerful learning management system
+ * published by ILIAS open source e-Learning e.V.
+ *
+ * ILIAS is licensed with the GPL-3.0,
+ * see https://www.gnu.org/licenses/gpl-3.0.en.html
+ * You should have received a copy of said license along with the
+ * source code, too.
+ *
+ * If this is not the case or you just want to try ILIAS, you'll find
+ * us at:
+ * https://www.ilias.de
+ * https://github.com/ILIAS-eLearning
+ *
+ *********************************************************************/
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\Attributes\After;
+use PHPUnit\Framework\Attributes\Before;
+
+/** PHPUnit captures error_log() only after expectErrorLog(), otherwise it goes to stderr: log to a file instead. */
+trait CapturesErrorLog
+{
+    private ?string $captured_error_log_file = null;
+    private string $error_log_ini_before_test = '';
+    private bool $captured_error_log_was_read = false;
+
+    #[Before]
+    protected function redirectErrorLogToFile(): void
+    {
+        $file = tempnam(sys_get_temp_dir(), 'lngerrlog');
+        $this->assertNotFalse($file);
+        $this->captured_error_log_file = $file;
+        $this->captured_error_log_was_read = false;
+        $this->error_log_ini_before_test = (string) ini_get('error_log');
+        ini_set('error_log', $file);
+    }
+
+    /** Whatever was logged and not asserted on is a failure, as unexpected output was before. */
+    #[After]
+    protected function restoreErrorLog(): void
+    {
+        $file = $this->captured_error_log_file;
+        if ($file === null) {
+            return;
+        }
+        $this->captured_error_log_file = null;
+        try {
+            $unexpected = $this->captured_error_log_was_read || !is_file($file) ? '' : (string) file_get_contents($file);
+        } finally {
+            ini_set('error_log', $this->error_log_ini_before_test);
+            @unlink($file);
+        }
+        if ($unexpected !== '') {
+            $this->fail('Unexpected error_log(): ' . $unexpected);
+        }
+    }
+
+    protected function loggedErrors(): string
+    {
+        $this->captured_error_log_was_read = true;
+
+        return $this->captured_error_log_file !== null && is_file($this->captured_error_log_file)
+            ? (string) file_get_contents($this->captured_error_log_file)
+            : '';
+    }
+
+    protected function assertLoggedErrorMatches(string $pattern): void
+    {
+        $this->assertMatchesRegularExpression($pattern, $this->loggedErrors());
+    }
+
+    protected function assertNothingLogged(): void
+    {
+        $this->assertSame('', $this->loggedErrors());
+    }
+}
diff --git a/...onents/ILIAS/Language/tests/ComponentTranslation/MigratedLanguageFileSyncEditableTest.php b/...onents/ILIAS/Language/tests/ComponentTranslation/MigratedLanguageFileSyncEditableTest.php
@@ -28,6 +28,8 @@
  */
 class MigratedLanguageFileSyncEditableTest extends MigratedLanguageFileSyncTestCase
 {
+    use CapturesErrorLog;
+
     /**
      * @return array<string, string>|null identifier => value
      */
@@ -59,8 +61,8 @@ public function testAnUnreadableOverlayYieldsTheShippedPoAloneAndIsReported(): v
         $this->seedOverlay(['greeting' => 'Moin']);
         file_put_contents($this->overlayBase() . '.po', "msgid \"kaputt\n");
 
-        $this->expectOutputRegex('/The local changes of module "stest" for "de" cannot be read, the shipped values are used/');
         $this->assertSame(['greeting' => 'Hallo'], $this->editable());
+        $this->assertLoggedErrorMatches('/The local changes of module "stest" for "de" cannot be read, the shipped values are used/');
     }
 
     /** For writing, the shipped values alone would drop the other local changes of the overlay: it throws instead. */
@@ -87,16 +89,19 @@ public function testWithoutClientDataDirectoryTheShippedPoAloneIsReturned(): voi
         $this->seedShipped(['greeting' => 'Hallo']);
 
         $this->assertSame(['greeting' => 'Hallo'], $this->editable(null));
-        $this->expectOutputString('');
+        $this->assertNothingLogged();
     }
 
     public function testAnUnreadableShippedPoThrows(): void
     {
         file_put_contents($this->shippedPo(), "msgid \"kaputt\n");
 
-        $this->expectOutputRegex('/cannot be read/');
-        $this->expectException(\RuntimeException::class);
-        $this->editable();
+        try {
+            $this->editable();
+            $this->fail('A RuntimeException was expected.');
+        } catch (\RuntimeException) {
+            $this->assertLoggedErrorMatches('/cannot be read/');
+        }
     }
 
     /**

diff --git a/components/ILIAS/Language/tests/FuzzyMarkerDefaultLanguageTest.php b/components/ILIAS/Language/tests/FuzzyMarkerDefaultLanguageTest.php
@@ -22,6 +22,8 @@
 /** ilObjLanguageExt::withFuzzyMarkers(): the "not translated yet" marker falls back to the default language. */
 class FuzzyMarkerDefaultLanguageTest extends ilLanguageBaseTestCase
 {
+    use CapturesErrorLog;
+
     /** @var list<string> */
     private array $queries = [];
 
@@ -62,11 +64,11 @@ private function markersWith(string $user_text, ?string $default_text): array
     public function testAMarkerMissingInTheUserLanguageComesFromTheDefaultLanguage(): void
     {
         // "lng" is shipped: the default language comes from the build (none here), never from lng_data
-        $this->expectOutputRegex('/There is no build of the language files/');
         $comments = $this->markersWith('-lng_not_translated-', 'Not translated en');
 
         $this->assertSame(['lng.#:#.a' => 'note - -lng_not_translated-', 'lng.#:#.b' => '-lng_not_translated-'], $comments);
         $this->assertSame([], $this->queries);
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     public function testAMarkerOfTheUserLanguageIsUsedWithoutFurtherQuery(): void
@@ -79,10 +81,10 @@ public function testAMarkerOfTheUserLanguageIsUsedWithoutFurtherQuery(): void
 
     public function testAMarkerMissingEverywhereStaysTheMissingKeyMarker(): void
     {
-        $this->expectOutputRegex('/There is no build of the language files/');
         $comments = $this->markersWith('-lng_not_translated-', null);
 
         $this->assertSame('-lng_not_translated-', $comments['lng.#:#.b']);
         $this->assertSame('note - -lng_not_translated-', $comments['lng.#:#.a']);
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 }
diff --git a/components/ILIAS/Language/tests/PoMigrationLoadLanguageModuleTest.php b/components/ILIAS/Language/tests/PoMigrationLoadLanguageModuleTest.php
@@ -50,6 +50,8 @@ public function module(): string
 #[PreserveGlobalState(false)]
 class PoMigrationLoadLanguageModuleTest extends ilLanguageBaseTestCase
 {
+    use CapturesErrorLog;
+
     protected function setUp(): void
     {
         parent::setUp();
@@ -288,8 +290,8 @@ public function testAShippedModuleWithoutABuildHasNoIdentifiersAndIsReported():
         );
 
         // a shipped module (lang/poll.pot) without a build: no identifiers, never the database
-        $this->expectOutputRegex('/There is no build of the language files/');
         $this->assertSame([], MigratedPoFixture::servedTexts('poll', 'de', false));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     /** "Migrated for a language" means a shipped `.po` exists: its absence yields no identifiers, not a missing overlay `.mo`. */
@@ -305,8 +307,8 @@ public function testNoIdentifiersAndNoReportWhenNoShippedPoExistsForThisLanguage
     public function testAShippedModuleIsRecognisedByItsTemplateWithoutADirectoryManager(): void
     {
         // tos is recognised by its shipped template without the component graph; there is no build
-        $this->expectOutputRegex('/There is no build of the language files/');
         $this->assertSame([], $this->callLoadFromMigratedLanguageFile('tos', 'de'));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     /**
@@ -409,10 +411,10 @@ public function testACachedModuleOfAShippedModuleWithoutABuildIsNeitherServedNor
             ['tos' => ['tos_agreement' => 'FROM THE lng_modules CACHE']]
         );
 
-        $this->expectOutputRegex('/There is no build of the language files/');
         $language->loadLanguageModule('tos');
 
         $this->assertSame('-tos_agreement-', $language->txt('tos_agreement'));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     /** Setup/CLI: no build, no component graph - a LanguageIdentifier of a shipped module has no value and never reaches lng_data/lng_modules. */
@@ -421,8 +423,8 @@ public function testAnIdentifierOfAShippedModuleWithoutBuildAndComponentGraphIsN
         $this->setGlobalVariable('ilDB', $this->databaseThatMustNotBeQueried());
         $language = $this->buildLanguageWithoutRunningConstructor('de', 'en');
 
-        $this->expectOutputRegex('/There is no build of the language files/');
         $this->assertSame('-tos_agreement-', $language->txt(PoMigrationLoadLanguageModuleTestTosIdentifier::AGREEMENT));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     /** The prefix index is built per manager: another manager (e.g. a test or a re-initialised container) is never answered from the old one; the first directory of a prefix wins. */

diff --git a/components/ILIAS/Language/tests/ShippedModulesNeverReadFromDatabaseTest.php b/components/ILIAS/Language/tests/ShippedModulesNeverReadFromDatabaseTest.php
@@ -36,6 +36,8 @@
 #[PreserveGlobalState(false)]
 class ShippedModulesNeverReadFromDatabaseTest extends ilLanguageBaseTestCase
 {
+    use CapturesErrorLog;
+
     private const string LANG_DIRECTORY = 'components/Vendor/Comp/lang/';
 
     private string $root;
@@ -118,7 +120,6 @@ public function testTheOverlayOfIliasIniIsServedAfterTheSetupCreatedBuildAndClie
         $this->buildShippedModule(false);
         $this->forbidDatabase();
 
-        $this->expectOutputRegex('/There is no build of the language files/');
         $this->assertSame('-greeting-', ilLanguage::_lookupEntry('de', 'zzs', 'greeting'), 'fresh installation: no client directory, no build');
 
         $this->buildShippedModule();
@@ -130,6 +131,7 @@ public function testTheOverlayOfIliasIniIsServedAfterTheSetupCreatedBuildAndClie
         MigratedTranslations::reset();
 
         $this->assertSame('Overlay', ilLanguage::_lookupEntry('de', 'zzs', 'greeting'));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     public function testTheClientDataDirectoryIsResolvedOncePerResetAlsoWhenMissing(): void
@@ -202,17 +204,17 @@ public function testWithoutABuildAShippedModuleHasNoValuesAndTheMissingBuildIsRe
         $this->buildShippedModule(false);
         $this->forbidDatabase();
 
-        $this->expectOutputRegex('/There is no build of the language files/');
         $this->assertSame('-greeting-', ilLanguage::_lookupEntry('de', 'zzs', 'greeting'));
+        $this->assertLoggedErrorMatches('/There is no build of the language files/');
     }
 
     public function testALanguageWithAPoButNotInTheBuildIsReportedAsNotBuilt(): void
     {
         $this->buildShippedModule(true, true);
         $this->forbidDatabase();
 
-        $this->expectOutputRegex('/ships a language file for "fr" that is not built/');
         $this->assertSame('-greeting-', ilLanguage::_lookupEntry('fr', 'zzs', 'greeting'));
+        $this->assertLoggedErrorMatches('/ships a language file for "fr" that is not built/');
     }
 
     public function testALanguageWithoutAPoHasNoValuesAndNoReport(): void
@@ -221,7 +223,7 @@ public function testALanguageWithoutAPoHasNoValuesAndNoReport(): void
         $this->forbidDatabase();
 
         $this->assertSame('-greeting-', ilLanguage::_lookupEntry('it', 'zzs', 'greeting'));
-        $this->expectOutputString('');
+        $this->assertNothingLogged();
     }
 
     /**
@@ -239,7 +241,7 @@ public function testANotInstalledOrInvalidLanguageHasNoValuesNoReportAndNoDataba
         $this->forbidDatabase(['en']);
 
         $this->assertSame('-greeting-', ilLanguage::_lookupEntry($lang_key, 'zzs', 'greeting'));
-        $this->expectOutputString('');
+        $this->assertNothingLogged();
     }
 
     public function testAModuleOfNoComponentIsStillReadFromTheDatabase(): void