RPI4 Raspbian 64 bit & LinuxCNC

That did not get me all the way there
I get stuck at "make" step.
this is the response.
make
Makefile:99: *** Makefile.inc must specify RTPREFIX and other variables. Stop.
pi@raspberrypi:~/linuxcnc-dev/src $

Try from ./configure onwards but with "./configure --with-realtime=uspace"

Nope both ways get the same error

configure: error: Required OpenGL header missing. Install it, or specify --disable-python to skip the parts of LinuxCNC that depend on Python
pi@raspberrypi:~/linuxcnc-dev/src $ make
Makefile:99: *** Makefile.inc must specify RTPREFIX and other variables. Stop.

Let's step back here.

What do you want?

I know you paid for the 8GB Pi. But you don't need 8GB to run LinuxCNC.

I think that the current LinuxCNC SD card image works on the 8GB Pi, but basically by limiting it to 3GB. Have you even tried this?

What is your goal here? If you just want to make parts, I would not start where you are now.

Fair point. I have no experience with LinuxCNC I am building a new machine. It as Slave Y axis and I wanted to be able to add a 4th Rotary axis at some point in the future. In my research LinuxCNC was rated high and has been around for a long time. I wanted a standalone system and I did not what to use on of the Chines offline controllers because I was concerned about my lack of experience and the 5 axis control.
So that is how I ended up at LinuxCNC. since I decided to use LinuxCNC I was talking to Peter at Mesa on that hardware that I needed and he told me about the 3G issue with the 8G Rpi4 and that elovalvo had a solution. so I seen this post and figured this is the version I wanted. I did not want high latency with my system and I have a 64 bit Rpi.
I am also still assembling my machine and the 7I96 borads are still on back order I have time to try to make this work. So I thought I would try to make it work.
Do you think I should go back to 32 Bit OS?

It's just that the use of LinuxCNC on the RPi is somewhat new territory. If you are not severely constrained spacewise it might be a lot more straight forward to use a regular PC with one of the premade ISO images.