Compile Linux Kernel ,RTAI and LinuxCNC from Source Code

I want to upgrade the gcc version? Which version of gcc does it need?

I was asking a question as to whether it could be a gcc issue.

As for upgrading gcc, that is way way out of the scope of these forums.

I reinstalled gcc7 and set it as the default compiler, but it still didn’t work. It doesn’t seem to be a problem with gcc
I don't know why you compile and generate the deb package will succeed

Did you compile the deb package in that Linux distribution? As you said, I installed your deb package under ubuntu16.04, and there really is a problem. Among them, there is no problem with the deb package of linux kernel and RTAI, but the deb package of linuxcnc has some lack of dependent packages, which seems to be not very easy to solve.
Thanks!

If you are trying to install deb packages on Ubuntu 16.04 that have been built for a later version you will have issues. There will be more than likely be package version that are unavailable or unavailable.
Whilst you may be able to install them from source it may cause issues else where.
As much as you don’t want hear it, the best option is to use the official distro for Linuxcnc or at least follow the team’s instructions for getting up and going.
And honestly unless there is unmovable reason to stick with 16.04 I move on to Bionic or 18.xx.
Once the gtk3 issues has been sorted 20.xx will be the way to go.

I will download Bionic right away, and then install and try those deb packages. Thank you

When running runtests, the following errors appear. Do these errors affect the running of linuxcnc?

Hi,Andy. When running runtests, the following errors appear. Do these errors affect the running of linuxcnc?

what is the meaning of "Which maths library did you build in to RTAI?"
This is the option that needs to be set when compiling RTAI? After I make menuconfig, there is no function library set in it. Which option is it? Can you describe it in more detail? Thanks