hi, I'm trying to use the GDBstub with a Nano and am getting the compiler error indicating multiple definitions of __vector_18.  I believe the problem is that both hardware serial and GDBstub both want to use the interrupt for USART RX.  I've had several conversations with chatGPT and it is recommending I disable compilation of HWSERIAL.  My project has a .ino file (containing #include<avr_debugger.h>) and other .h and .cpp files.  As recommended by chatGPT, I tried #define DISABLE_HWSERIAL at the top of my .ino file but get the same error.  Next it said: DISABLE_HWSERIAL is too late for the Arduino core build. By the time your .ino is seen, HardwareSerial.cpp has already been compiled.  It recommends putting DISABLE_HWSERIAL as a Compiler define.  I'm not able to find where that goes.....sooooo, if this all sounds plausible to a human reader, please tell me where to find in VisualMicro the place to enter DISABLE_HWSERIAL.  I'm using Visual studio 2026 and the accompanying Visualmicro.  Of course, chatGPT could be way off base...it is like having a smart friend that is not always right

Any help here is much appreciated.....jim

  Thank you!  Changing from debug to release did the trick! This will be my first time using the GDBstub and the VS debugger.....fingers crossed    
I've used the Visual Micro debugger a fair amount but really miss the ability to step, step into, and step over.  Thanks again....jim