Re: [Blog/Cookbook?] On multiple Guix profiles and manifests

[Konrad Hinsen]

Am 14.10.19 um 09:27 schrieb Pierre Neidhardt:

> > However, I wonder why nobody has implemented
> > "guix environment --profile=/path/to/my/profile".
>
> Note that there is the "--manifest" option to "guix environment".
>
> This brings up another "pro" for manifest: Right now it's possible to
> create environments out of manifests while it's not possible to create
> environments out of profiles without Chris' hack.

When I explain Guix, I start with environments, which I consider that 
more fundamental concept, and then introduce profiles as persistent 
environments. From that perspective, creating an environment from a 
profile makes no sense, though it may be useful as a convenience 
function for some needs (not mine). Manifests are persistent 
*specifications* of environments, which do make sense (a lot, in fact).

> A question that I believe has been brought up before: is it possible to
> specify multiple manifests from the command line, such as to provide the
> union of the manifests?
>
> Even better: what high-level functions to manipulate manifests, such as
> "manifest-union", "manifest-difference"?

Union is OK, difference isn't. A manifest is not just any set of 
packages, it's a set of packages that has no dependencies outside of the 
set.

This sounds like the beginning of another chapter for the cookbook: 
package lists, manifests, bags, etc. What are the differences, and when 
should I use what?

Which reminds me that when working on the command line, the "manifest" 
option in practice always refers to a package list that is then 
converted to a manifest. And most people *want* to work at the package 
list level. And then differences make sense again. It's all a bit of a 
mess...

Cheers,
  Konrad.