From 66d460c19b8fc9fafedacce02e306951e78c37a5 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Mon, 28 Oct 2019 16:53:35 +1100
Subject: [PATCH] GCS_MAVLink: correct format in short-write panic message

---
 libraries/GCS_MAVLink/GCS_MAVLink.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/GCS_MAVLink/GCS_MAVLink.cpp b/libraries/GCS_MAVLink/GCS_MAVLink.cpp
index ed781b50d4..c554730705 100644
--- a/libraries/GCS_MAVLink/GCS_MAVLink.cpp
+++ b/libraries/GCS_MAVLink/GCS_MAVLink.cpp
@@ -130,7 +130,7 @@ void comm_send_buffer(mavlink_channel_t chan, const uint8_t *buf, uint8_t len)
     const size_t written = mavlink_comm_port[chan]->write(buf, len);
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
     if (written < len) {
-        AP_HAL::panic("Short write on UART: %lu < %u", written, len);
+        AP_HAL::panic("Short write on UART: %lu < %u", (unsigned long)written, len);
     }
 #else
     (void)written;