On Fri, Jan 14, 2022 at 09:47:52AM +0100, Ludovic Courtès wrote: > > Recently, Matt pointed out that profile collisions can be confusing and > > difficult to resolve: > > > > https://lists.gnu.org/archive/html/guix-devel/2022-01/msg00115.html > > I don’t see the words “profile” and “collision” here; maybe that was > upthread?
I pointed to this blog post, which was linked from that email: > > Specifically see this blog post: > > http://excalamus.com/2021-10-06-guix-debug.html It's the story of an attempt to learn what the "conflicting entries" message means and how to resolve it. > Currently, on profile collisions, the error message shows where the > collision originates and a hint on how to work around it. Perhaps the > hint is sometimes wrong (in which cases?), or perhaps it’s too terse? > Can it be improved? The hint is perfectly clear, when you understand "profiles" and "propagation". It's like I said later in my message: People use Guix without knowing very much about it. That's surprising to me, because I started using Guix *because* I learned about profiles and how they are used: it's one of the core innovations of Guix / Nix, to implement unprivileged package management. But nevertheless, people are using Guix without understanding how it works. And it's hard to learn about Guix when you are dealing with a profile collision that you don't understand at all. For many people, that is not a good moment to start learning. On top of that, profile collisions are an error state that we can't fix as a bug: we have to give users the knowledge to resolve the collisions themselves. For example, the blog post that I linked to ends with "Lessons Learned", which includes this: ------ What is a profile? A profile is a directory of symlinks located at ~/.guix-profile. Propagated inputs can cause conflicts Propagated inputs are treated somehow differently. It's still not 100% clear how or why, but it's good to know they're a potential source of errors. ------ This person spent a lot of time trying to understand the situation and writing the blog post, but their understanding is still rather weak. That's why I propose a Cookbook chapter that specifically addresses profile collisions, to help new users go from "oh no, an error message" to "aha!" > The definition of what a profile is is another topic. Currently the > term “profile” is defined in “Getting Started”: > > https://guix.gnu.org/manual/en/html_node/Getting-Started.html#index-profile > > It’s very much defined in passing though. How can we improve on that? I think this part of the manual is fine and can stay as it is. > In some early talks we had illustrations of the symlink forest of a > profile borrowed from Eelco Dolstra’s own talks on the matter; see for > instance p. 17 of <https://guix.gnu.org/guix-fosdem-20140201.pdf>. I > stopped using it because I think those symlinks are an implementation > detail and it doesn’t help to focus on symlinks (and hashes and all > that) when giving an overview of the tool. Now, perhaps that > illustration could be useful in the manual. > > WDYT? The illustrations of the symlink forest were *extremely* helpful to me when learning how Guix implements unprivileged package management. I think that later talks from the 2015-2017 era refined the illustrations to be even more clear. I'm sorry if the use case for my proposal is still unclear. I can work on the Cookbook chapter myself.
