cmake-buildsystem
To use the cmake build system instead of the make-driven one, do:
cmake /path/to/lammps/source/cmake
(please note the cmake directory as the very end)
To enable package, e.g. GPU do
cmake /path/to/lammps/source/cmake -DENABLE_GPU=ON
cmake has many many options, do get an overview use the curses-based cmake interface, ccmake:
ccmake /path/to/lammps/source/cmake
(Don't forget to press "g" for generate once you are done with configuring)