cd into the directory run: go get

The cgo compilation step will fail. Next important steps: As listed in the ws2811.go file ensure to copy ws2811.h, rpihw.h, and pwm.h in a GCC include path (e.g. /usr/local/include) and libws2811.a in a GCC library path (e.g. /usr/local/lib).

The header files are in /home/pi/go/pkg/mod/github.com/jgarff/rpi_ws281x......

The library (.a) file is in /home/pi/go/pkg/mod/github.com/jgarff/rpi_ws281x.../

Run go get one more time, and it should succeed, but if you still have trouble, cd to /home/pi/rpi_ws281x/

run sudo apt-get install scons

after the installation, from the same folder run scons

now you can change to /home/pi/pi-led/ and run go get and go build