Per @hathach request

Author: henrygab

cores/arduino/WInterrupts.c

@@ -250,8 +250,9 @@ void detachInterrupt(uint32_t pin)
  * External Interrupt Controller NVIC Interrupt Handler
  */
 #if defined(__SAMD51__)
-void InterruptHandler(__attribute__((unused)) uint32_t i)
+void InterruptHandler(uint32_t unused_i)
 {
+  (void)unused_i;
   // Calling the routine directly from -here- takes about 1us
   // Depending on where you are in the list it will take longer
 

libraries/Servo/src/samd/Servo.cpp

@@ -172,8 +172,9 @@ static inline void resetTC (Tc* TCx)
     while (TCx->COUNT16.CTRLA.bit.SWRST);
 }
 
-static void _initISR(Tc *tc, uint8_t channel, __attribute__((unused)) uint32_t id, IRQn_Type irqn, uint8_t gcmForTimer, uint8_t intEnableBit)
+static void _initISR(Tc *tc, uint8_t channel, uint32_t id, IRQn_Type irqn, uint8_t gcmForTimer, uint8_t intEnableBit)
 {
+    (void)id;
     // Select GCLK0 as timer/counter input clock source
 #if defined(__SAMD51__)
     int idx = gcmForTimer;           // see datasheet Table 14-9