Build time can be reduced by using multiple cores of your processor.

Parallelization for make:

make -j8

Parallelization for cmake:

cmake --build <bindir> -- -j 8

Sometimes you cannot pass parameters directly to make. For example you are installing a python module using

python install

Setup script doesn’t accept parameters. Then you could pass them through environment variables:

export MAKEFLAGS="-j 8"

see also