This helps building LineageOS from source like described in https://wiki.lineageos.org/devices/i9100/build
Docker needs to be installed in order to use this scripts. Then just run
./make.sh
and the an docker image will be built and an container started. In the container shell, run
download.sh
in order to download the sources (~20 GB - takes some time) and then run
buildAndroid.sh
in order to start building.