Install avr-libc by entering the following commands in the terminal:
sudo apt update sudo apt install avr-libc
Description:
Standard C library for Atmel AVR development
Standard library used to the development of C programs for the Atmel AVR micro controllers. This package contains static libraries as well as the header files needed.
Version: 1:2.0.0+Atmel3.6.0-1
Section: universe/otherosfs