LinuxCnC 2.9 vs 2.8 Advantages ?

 Don't let my rating fool anyone I am still very much a Noob . So what are the advantages of ver. 2.9 VS 2.8 ?
From what I have read 2.9 has Python 3.# support where as 2.8 has Python 2.# support . Though I think 2.8.2 supports
Python 3 correct me if I am wrong. Other then that what are the other advantages?

There is really no advantage unless you require 2.9's advantages
I started with Linuxcnc  when 2.7 was the release version but I wanted to run a gantry using the joint axes branch which was an experimental branch in master.. Before i got to that, It was committed into master branch (then 2.8).

Since then I have needed features of master branch (now 2.9) to run my plasma table so I've always been there.

But if you are running master, its pretty pointless if you do not compile from source. Over the years, I have run experimental branches and even cloned other people's forks of linuxcnc

But heck that was easy given I had to compile the kernel to get PREEMPT_RT back in those days so its a lot easier to install linuxcnc today.

I looked into LinuxCnC back when 2.7.14 was released. If I remember correctly ver. 2.7 didn't support Ethernet. however 2.8.0 did.
all the machines I am running currently use Ethernet. The 7i76E is cheaper then using the 5i25/6i25 and 7i76 combo.
So what are the 2.9 advantages ?

The big one for me is that running 2.9 on Bullseye gives vastly superior support for modern hardware as it is more likely to have driver support in the 5.10 linux kernel.
I would not bother running 2.9 on Buster.
There has been a lot of development since the release of 2.8. There will be many more features I do not know about. Things I care about:
QTplasmac is the default plasma config and its only available in 2.9.
2.9 is what is now in the Debian repositories (on the 2.16 kernel)
There is a brand new method to overwrite the homing procedures from your ini file which is of interest  for ethercat users. I want to see if I can use that to support internal homing on my devices.
Eliminating Python 2 was a good step for me as configs broke for me earlier but that now seems to have been resolved in Buster.

The downside is there is no deb installation for Bullseye so you need to compile from source or roll debian forward 2 versions and install from the Debian repositories.

Did I say driver support?
 

2.7's limitation was the near obsolete RTAI  kernel when Mesa card required PREEMPT_RT
The solution back then was to run Mint 17.3 or 18, compile the kernel and install from the buildbot or compile the source.
There was even a popular how to here on the forum (written after I did it of course
And then there was no 7i76e support until after i built my config manually and after the release of 2.8
I actually remember testing pncconf for Mr Morley but I have never really used it (other than to make a really quick config I overwrite by hand.)

Cool that helps a lot. I am sure others who are just getting started would probably be asking the same questions. I know now
why some either could not or would not revert back to 2.8 from 2.9. if they were having issues.

If you install Debian Bullseye or other later kernels, there is no going back to 2.8 because Python 2.7 does not exist. For me that and driver support in later kernels are the whole point of the Bullseye exercise.

The  best guide to Installing Linuxcnc On Bullseye (5.10 kernel) is here:
www.qtpyvcp.com/install/bullseye.html

If you wish to be a bit more adventurous, you can upgrade Debian to the unstable branch by editing your sources.list without compiling anything.

Have a coffee handy it will take a while.

This version of linuxcnc is a few months old. But its not necessary to build from source.
If you need the absolute latest and greatest, you still need to compile from source. Eg if you want to use QTPlasmac which gets almost daily updates. But the additional dependencies is significantly reduced.

Building from source is not hard. Its described in the docs here
linuxcnc.org/docs/devel/html/code/building-linuxcnc.html

Note you do not need to compile using make if you build the debs.

Note I did not say you had to use run in place if you used 2.9. Thats all I used for about 5 years. I usually now just build and install the debs as the QTPYVCP instructions do.


Now Rod waits for the lecture about using debian unstable being unsafe. That is not really the case, its just a rolling release and is used as a base for some distros.

 

Well for me personally I will be currently sticking with my copy of the BeagleBrains special. ( Linux Mint 19.3 and LinuxCNC 2.8.0 )
When Debian and 2.9 are ready for the main stream I will give that a test drive. Last time I tried to download Debian and 2.8.0
I had a fit getting the Ethernet to work.