wget -c https://aos.ion.nu/sourcemirror/db-18.1.25.tar.gz # Mirrored because registration-walls are bad
tar -xzf db-18.1.25.tar.gz
cd db-18.1.25
mkdir -p build
cd build
../dist/configure --prefix="/usr" --enable-cxx
make # Doesn't mind -j#
make install