diff -urN ../roundcubemail-1.6.1.orig/program/lib/Roundcube/rcube.php ./program/lib/Roundcube/rcube.php
--- ../roundcubemail-1.6.1.orig/program/lib/Roundcube/rcube.php	2023-01-23 22:03:14.000000000 +0200
+++ ./program/lib/Roundcube/rcube.php	2023-04-12 11:52:46.063087000 +0300
@@ -1381,6 +1381,35 @@
     }
 
     /**
+     * Format backtrace.
+     *
+     * @param array $backtrace Backtrace array
+     * @see debug_backtrace()
+     * @param int   $limit     Limit the number of stack frames formatted. By default (limit=0) it formats all stack frames.
+     */
+    public static function debug_backtrace_as_string($backtrace, $limit = 0)
+    {
+        $i = 0;
+        $res = [];
+        $res[] = 'Stack trace:';
+        foreach ($backtrace as $backtrace_item) {
+            if (($limit == 0) or ($i < $limit)) {
+                $res[] = sprintf("#%d %s(%d): %s%s%s()",
+                    $i,
+                    (!empty($backtrace_item['file']) ? $backtrace_item['file'] : ''),
+                    (!empty($backtrace_item['line']) ? $backtrace_item['line'] : 0),
+                    (!empty($backtrace_item['class']) ? $backtrace_item['class'] : ''),
+                    (!empty($backtrace_item['type']) ? $backtrace_item['type'] : ''),
+                    (!empty($backtrace_item['function']) ? $backtrace_item['function'] : '')
+                );
+                $i++;
+            }
+        }
+        if (($limit == 0) or ($i < $limit)) $res[] = sprintf("#%d {main}", $i);
+        return(implode("\n", $res));
+    }
+
+    /**
      * Throw system error, with optional logging and script termination.
      *
      * @param array|Throwable|string|PEAR_Error $arg Error object, string or named parameters array:
diff -urN ../roundcubemail-1.6.1.orig/program/lib/Roundcube/rcube_db.php ./program/lib/Roundcube/rcube_db.php
--- ../roundcubemail-1.6.1.orig/program/lib/Roundcube/rcube_db.php	2023-01-23 22:03:14.000000000 +0200
+++ ./program/lib/Roundcube/rcube_db.php	2023-04-11 14:49:21.326443000 +0300
@@ -566,6 +566,7 @@
                 rcube::raise_error([
                         'code' => 500, 'type' => 'db', 'line' => __LINE__, 'file' => __FILE__,
                         'message' => $this->db_error_msg . " (SQL Query: $query)"
+                        . "\n" . rcube::debug_backtrace_as_string(debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS)) . "\n  thrown"
                     ], true, false);
             }
         }