Re: Thoughts on making Guix even better

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

"Raghav Gururajan" <raghavgururajan@disroot.org> skribis:

> The guix system transactions are NON-MODULAR. That is, you cannot selectively reconfigure certain parts of the system. For example, you either reconfigure the system as a whole (or) you do not reconfigure the system at all.
>
> IMPLICATIONS:
>
> Lets assume we have 5 packages in profile. Package 1, 3 and 5 has non-critical updates. Package 4 has non-critical update but it breaks. Package 2 has critical update (CVE). We can either upgrade all packages except package 4 (or) we can upgrade only package 2.
>
> Lets assume we have 5 services/packages in system. Package/Service 1, 3 and 5 has non-critical updates. Package/Service 4 has non-critical update but it breaks. Package/Service 2 has critical update (CVE). Now, when we reconfigure the system, all packages/services will upgrade, package/service 4 will break the system. We can of course do '--roll-back' and take the system to previous working state. But that will leave the system with critical vulnerability. Therefore, we cannot reconfigure package/service 2 or any other parts of the system, until the package/service 4 is fixed. This window/gap puts guix system at great risk and instability.

On one hand, I agree that it’d be nice to be able to update just parts
of the system, like you explain.

On the other hand, that would lead to an unknown and possibly
unreproducible system state, which defeats what declarative
(“non-modular”) system upgrades bring.

Besides, I don’t see how one could introduce this “imperative” approach
at the system level, technically.

All in all, it would be best if the situations that make “modular system
upgrades” appear necessary didn’t occur in the first place.

Thoughts?

Ludo’.