Ubuntu to Ubuntu Cross C++ Development

# Install the necessary tools:
sudo apt install ubuntu-dev-tools
# Then create a schroot environment for the arm64 environment, using Ubuntu 
# Impish (remember the name you used, you'll need it later):
mk-sbuild --arch=arm64 --skip-proposed --skip-updates --skip-security --name=rpi3-impish impish
# If this is the first time you run mk-sbuild, you'll have to follow some 
# instructions. Since we won't be publishing any software, you can simply accept
# the default configuration. Afterwards, reboot or log out and back in again, as 
# instructed. Alternatively, use 
su - $USER # to flush group membership.
# Then run the command again, this time it will actually create the schroot:
mk-sbuild --arch=arm64 --skip-proposed --skip-updates --skip-security --name=rpi3-impish impish
# Install some dependencies in the schroot. Use the sbuild-apt wrapper around 
# the apt-get tool, and give it the name of the schroot you created earlier,
# with the architecture as suffix:
sudo sbuild-apt rpi3-impish-arm64 apt-get install libboost-all-dev
# Download and extract the cross-compilation toolchain:
wget -qO- https://github.com/tttapa/docker-arm-cross-toolchain/releases/latest/download/x-tools-aarch64-rpi3-linux-gnu.tar.bz2 | tar xJ -C ~/opt
# Add the toolchain to your path:
export PATH="$HOME/opt/x-tools/aarch64-rpi3-linux-gnu/bin:$PATH"
# Download the repository with the example CMake C++ project:
git clone https://github.com/tttapa/RPi-Cross-Cpp-Development.git
# Enter it:
cd RPi-Cross-Cpp-Development
# Replace the schroot name in the toolchain file by the name used earlier:
sed -i 's/schroot-name-arm64/rpi3-impish-arm64/' cmake/aarch64-rpi3-linux-gnu.cmake
# Configure the project for cross-compilation:
cmake -S. -Bbuild -DCMAKE_TOOLCHAIN_FILE="$PWD/cmake/aarch64-rpi3-linux-gnu.cmake"
# Build the project:
cmake --build build -j
# Install the project into the staging area:
cmake --install build
# Install the dependencies on the Raspberry Pi:
ssh RPi3 sudo apt-get install -y libboost-program-options1.74.0
# Copy the “Hello World” example program to the Raspberry Pi:
ssh RPi3 mkdir -p '~/.local/bin'
scp ~/RPi-dev/staging-aarch64-rpi3/bin/hello RPi3:~/.local/bin
# Run the example program:
ssh RPi3 bash --login -c hello
# Or simply log in using
ssh RPi3
# and then run the program there:
hello

# Copy the toolchain's gdbserver to the Pi:
scp ~/opt/x-tools/aarch64-rpi3-linux-gnu/aarch64-rpi3-linux-gnu/debug-root/usr/bin/gdbserver RPi3:~
# Install it:
ssh RPi3 sudo mv gdbserver /usr/local/bin
# Test it:
ssh RPi3 gdbserver --version
# Start GDB with the hello program on your computer:
aarch64-rpi3-linux-gnu-gdb ~/RPi-dev/staging-aarch64-rpi3/bin/hello
# Inside of GDB, set the sysroot:
set sysroot /var/lib/schroot/chroots/rpi3-impish-arm64
# Select and start the target:
target remote | ssh RPi3 gdbserver - '~/.local/bin/hello' --name Pieter
# Run program:
continue
# Exit GDB:
quit