How to enable compile error highlighting

Development Tools IDE 2.x
2

Hi @Sluice. Please try this:

  1. Select File > New Sketch from the Arduino IDE menus.
  2. Add the following line to the top of the sketch code:
    #error "Oops!"
  3. Select Tools > Board > Arduino AVR Boards > Arduino Uno from the Arduino IDE menus.
  4. Select Sketch > Verify/Compile from the Arduino IDE menus.
  5. Wait for the compilation to fail.

Do you now see an error highlight on the first line of the sketch?:

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