jenkinsfile - watch screen test 7b intern again

api/Jenkinsfile.ble_test

@@ -92,7 +92,7 @@ pipeline {
                         while screen -list | grep -q "ble_test_${TEST_HASH}"; do
                             # `tail -f` streams the file; the read-loop ensures line-by-line flush
                             tail -n +1 -f /tmp/ble_test_${env.TEST_HASH}.log | while IFS= read -r line; do
-                                echo "$line"
+                                echo "\$line"
                             done
                         done
                     """