Installation v2.9.7 linuxcnc in November 2025.

I downloaded the image of disk 2.9 and allowed network connection during installation. After installation, it was loaded normally, everything is working, linuxcnc-uspace.
We follow the instructions - 
apt-get update
apt-get install linuxcnc

linuxcnc.org/docs/2.9/html/getting-start...#cha:Installing-RTAI
He swears, there is no such package! The list of sources indicates -
deb linuxcnc.org bookworm base



I run synaptic, the kernel is 5.4.258-rtai
I order it to be installed and heads - 

Error in published instruction. It should actually be -

vi sources.list.d/linuxcnc-uspace.list

deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/linuxcnc.gpg.key.binary.gpg] www.linuxcnc.org/ bookworm base 2.9-uspace 2.9-rt
 

So, it doesn't work.

To begin with, we had to solve the problems of inaccuracy of the installation description instructions. The downloaded attribute immediately after installation shows us v2.9.7 userspace. In order to install 2.9.2 rt you had to -

1. Overcome the distribution configuration error by removing the file stub for the raspberry -
forum.linuxcnc.org/38-general-linuxcnc-q...d-apt-problem#332403
sudo rm /etc/{initramfs/post-update.d/,kernel/{postinst.d/,postrm.d/}}z50-raspi-firmware

2.then you need to fix the first line of the file by adding 2.9-rt to its end
vi /etc/apt/sources.list.d/linuxcnc-uspace.list
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/linuxcnc.gpg.key.binary.gpg] www.linuxcnc.org/ bookworm base 2.9-uspace 2.9-rt

3. then you need to completely remove version 2.9.7
forum.linuxcnc.org/9-installing-linuxcnc...tall-rtai-got-errors
-
apt-get purge linuxcnc-uspace
apt-get purge linuxcnc-doc*

4. then you need to put the kernel (and only the kernel!)
wget www.linuxcnc.org/dists/bookworm/base/bin...ai-amd64-2_amd64.deb
dpkg -i linux-image-5.4.258-rtai-amd64_5.4.258-rtai-amd64-2_amd64.deb

5. This new kernel will now appear in boot options, you need to reboot the computer by selecting this particular kernel 5. And only now supply additional components -
wget www.linuxcnc.org/dists/bookworm/base/bin...xcnc-delta_amd64.deb
dpkg -i rtai-modules-5.4.258_5.3.3-linuxcnc-delta_amd64.deb

Now you can apt-get update + apt-get update

A running real-time kernel will always show 100% CPU load and does not need a swap. latensy-test starts and shows normal numbers.

An attempt to start the existing machine configuration leads to a system crash and reboot. Okay, stepconf and I create a new configuration, extremely simple. I launch it and also get a reboot.

Debug file information:
/usr/bin/linuxcnc: line 977:913 Segmentation error $EMCDISPLAY -ini "$INIFILE" $EMCDISPLAYARGS $EXTRA_ARGS
/usr/bin/milltask exiting

How to overcome this problem?
A discussion of the problem has been initiated here, but there is no solution
forum.linuxcnc.org/18-computer/51070-fro...-kernel-rtai-5-4-258