When I run linucnc, why it always tells me "Xenomai:/dev/rtheap is missing"

 Hi,
    I built a RT system using Ubuntu 20.04+Linux 4.19.279+xenomai3.1. I successfully compiled linuxcnc 2.10.0. When I run the linuxcnc, it always shows me an error message "Xenomai:/dev/rtheap is missing". I also run other linuxcnc versions like 2.8. I got the same error message. Please tell me how to solve this problem!

Is there any particular reason for using such old Linux/Kernel?
Use the official ISO from the downloads page, if there is not need for anything special.

Hi,
I don't agree with you. The reason why I use 4.19 kernel, Xenomai ipipe only supports up to 5.4 version.Have you ever seen this topic:https://forum.linuxcnc.org/9-installing-linuxcnc/43981-how-build-linuxcnc-with-xenomai3
You can go to see the last reply. fsabbatini only uses 4.14 kernel, and linuxcnc runs properly.

I don't think this is a issue related directly to Linuxcnc, it is more than likely an issue with the kernel config or the installation of the kernel. Maybe post tin the original thread, the OP might be around.

Maybe helpful here
yhbt.net/lore/all/5600F8DE.30705@xenomai.org/

I wish people would refer to the Downloads page and the docs before trying to implement stuff on old hardware and kernels.
One of the devs put a huge effort into retaining xenomai compatability.
Please start here:  linuxcnc.org/downloads/

Hi,
Fortunately, I solved this problem."rtheap is missing." is not the main reason. I reinstalled the xenomai using deb packages. The compiling command is "debuild -us -uc". I installed four packages.And then I think the Linuxcnc 2.9 can detect that the environment is xenomai.You'd better refer to this page " www.linuxcnc.org/docs/devel/html/code/building-linuxcnc.html ." and continue to finish compilation.
When you encountered "<posix/pthread.h> can't be found.", you should change <posix/pthread.h> to <cobalt/pthread.h> and add additional head files "#include <errno.h> #include <string.h> #include <stdio.h>".