Check if var debugMode exists

Closes #21150 a second time.
2nd appearance of debugMode may not seen in first fix.

diff --git a/core/templates/exception.php b/core/templates/exception.php
index f0bf171be648f8a86c30cf431187baea60c8bc2c..9fd19d5a8b17da9b1fb9223290672f342251c140 100644 (file)
--- a/core/templates/exception.php
+++ b/core/templates/exception.php
@@ -23,7 +23,7 @@ style('core', ['styles', 'header']);
                <?php endif; ?>
        </ul>
 
-       <?php if ($_['debugMode']): ?>
+       <?php if (isset($_['debugMode']) && $_['debugMode'] === true): ?>
                <br />
                <h3><?php p($l->t('Trace')) ?></h3>
                <pre><?php p($_['trace']) ?></pre>