Build debian 10:
cd build/release
cmake -G Ninja -DCMAKE_C_COMPILER=gcc-9 -DCMAKE_CXX_COMPILER=g++-9 -DCMAKE_INSTALL_PREFIX=/opt/Kicad-7.0.0 -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_FLAGS=-fuse-ld=lld ../../
ninja -j(USE CPU CORE / THREAD NUM)
Wait...
sudo ninja install

Build debian 11:
cd build/release
cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/opt/Kicad-7.0.0 -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_FLAGS=-fuse-ld=lld ../../
ninja -j(USE CPU CORE / THREAD NUM)
Wait...
sudo ninja install

build kicad 6:
cd build/release
cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/opt/Kicad-6.0.1 -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_FLAGS=-fuse-ld=lld ../../
ninja -j(USE CPU CORE / THREAD NUM)
Wait...
sudo ninja install