Compiler warning, I'm at a loss for understanding why

[JohnRob]

I'm using the IDE 2.1.0 with a SAMD21G board. My program seems to be working correctly and I am in the process of tweaking the error handling and display.
With some simple changes I am getting a compiler warning. I realize it's only a warning but for the life of me I can't see what the compiler see to flag a warning.

Can anyone see what I may be missing?

Thanks

function

void init_TypeK(void)
{
   // doesn't really initialize, simply reads the error bit
   bool error = false;                   <<======================= line 411
   int16_t gRawData = 0;
   //digitalWrite(TC_CSn, LOW);
   //delayMicroseconds(10);           // spec is 1µs
   digitalWrite(TC_CSn, HIGH);
   //delay(1);

// read the MSB only (i.e. D31 - D16)
   SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE0)); //  ??? see .h line35
   digitalWrite(TC_CSn, LOW);       //set CS low to read SPI interface
   gRawData = SPI.transfer16(0x0000);   // TypeK is read only, doesn't matter what is sent in SPI.transfer16(0x000)
   digitalWrite(TC_CSn, HIGH);    // deselect
   SPI.endTransaction();
   if (gRawData & 0b0001){
      error = true;                                            <<-------------------------- where used
   }  // in the MSB, the fault bit (D16) is available
}

Compiler warning:

C:\Users\john\Documents\Arduino\BoilerLoggingApp\BoilerLoggingApp.ino: In function 'void init_TypeK()':
C:\Users\john\Documents\Arduino\BoilerLoggingApp\BoilerLoggingApp.ino:411:9: warning: variable 'error' set but not used [-Wunused-but-set-variable]
bool error = false;
^~~~~
Sketch uses 34800 bytes (13%) of program storage space. Maximum is 262144 bytes.
Global variables use 4548 bytes (13%) of dynamic memory, leaving 28220 bytes for local variables. Maximum is 32768 bytes.

[sterretje]

You don't use the variable error e.g. as a return value or in an if statement hence the warning; you only assign a value to it.

E.g.

if (gRawData & 0b0001){
      error = true;
   }  // in the MSB, the fault bit (D16) is available
if (error == true)
{
  // do something
}

[JohnRob]

Thank I think I just realized that.