Selected board depends on 'arduino' core (not installed) When I load the Arduino IDE with Board: Pololu A-Star 32U4 selected, I see:

The current selected board needs the core 'arduino:arduino' that is not installed.


I installed the board manually via these instructions.

When verifying the initial empty sketch, I see:

Arduino: 1.8.8 (Linux), Board: "Pololu A-Star 32U4"

The current selected board needs the core 'arduino:arduino' that is not installed.
/usr/share/arduino/arduino-builder -dump-prefs -logger=machine -hardware /usr/share/arduino/hardware -hardware /home/ravi/Arduino/hardware -tools /usr/share/arduino/tools-builder -libraries /home/ravi/Arduino/libraries -fqbn=pololu:avr:a-star32U4 -ide-version=10808 -build-path /tmp/arduino_build_299010 -warnings=none -build-cache /tmp/arduino_cache_842714 -prefs=build.warn_data_percentage=75 -verbose /tmp/untitled689103723.tmp/sketch_feb05a/sketch_feb05a.ino

Selected board depends on 'arduino' core (not installed).

Error compiling for board Pololu A-Star 32U4.


How do I prevent this error and compile a sketch?
I needed to install the boards package for:

Arduino AVR Boards


Under Tools -> Board -> Board Manager