What's safe to update?

Running a Debian system the Update Manager shows lots of security updates + 3 from LinuxCNC (from version 1:2.6.2 to 1:2.7). I recall being uncertain about which Ubuntu related updates to install and which to avoid.
As a general rule, is it OK to install whatever Debian Update Manager suggests?

Hi

The update manager is no better in Debian, I think it is exactly the same program. (part of Synaptic)

.................. + 3 from LinuxCNC (from version 1:2.6.2 to 1:2.7).

You should not be getting an option to upgrade to 2.7. It should just show 1:2.6.3 which is the latest 2.6 version
I will have to boot a partition with the distro installed on it later and see what it offers me.

As a general rule, is it OK to install whatever Debian Update Manager suggests?

Unfortunately you need to look at the offerings and exclude any kernel updates (unless they come from linuxcnc.org) likewise kernel-headers if you have them installed.
The overwhelming majority of updates will be fine and sometimes necessary to fix security holes etc

regards

I booted my clean(ish) distro install partition and started Update-Manager

This is what you should see when opening Settings > Other software

If you are being offered the master-rt updates, then you must have all the check boxes ticked. Un-set all the ones for the buildbot and you should just be
offered the official release upgrades for 2.6.x

[attachment:1]Selection_002.jpg[/attachment

regards]