How to add gcc-arm-none-eabi to Ubuntu

sudo apt remove gcc-arm-none-eabi

Download the Linux x86_64 Tarball. Replace (version) with you downloaded version.
E.g. version 10.3-2021.07 -> gcc-arm-none-eabi-10.3-2021.07

Unpack it:

sudo tar xjf gcc-arm-none-eabi-(version).bz2 -C /usr/share/

Link it:

sudo ln -s /usr/share/gcc-arm-none-eabi-(version)/bin/arm-none-eabi-size /usr/bin/arm-none-eabi-size
sudo ln -s /usr/share/gcc-arm-none-eabi-(version)/bin/arm-none-eabi-gcc /usr/bin/arm-none-eabi-gcc 
sudo ln -s /usr/share/gcc-arm-none-eabi-(version)/bin/arm-none-eabi-g++ /usr/bin/arm-none-eabi-g++
sudo ln -s /usr/share/gcc-arm-none-eabi-(version)/bin/arm-none-eabi-gdb /usr/bin/arm-none-eabi-gdb

Check if it worked:

arm-none-eabi-gcc --version
arm-none-eabi-g++ --version
arm-none-eabi-gdb --version
arm-none-eabi-size --version