I am attempting to install the x11/nvidia-driver. Unfortunately, it will not install. This is the error message, which is emitted immediately when attempting to build the port.
/usr/ports/x11/nvidia-driver # make
===> nvidia-driver-440.31 requires kernel source files in SRC_BASE=/usr/src.
*** Error code 1
make: stopped in /usr/ports/x11/nvidia-driver
The "/usr/src" directory is in fact, completely empty.
So, what's the actual issue?