Add dependents ("via ..." comments) in export command

[zmeir]

Adding dependency trace/parent comments ("via ...") to the export command output.
This is a similar behavior to the pip compile output.

Note to the eager reviewer:

First of all - thanks!
Secondly, this is still a very rough draft. These are the first lines of code I've ever written in Rust. This is still mostly an educational/fun exercise for myself. If opening a Draft PR is creating too much noise - I apologize and I will close it until it is ready.

Summary

Resolves #7777

Test Plan

• manual command execution
• update expected output in tests

[charliermarsh]

What is the purpose of this sort?

[charliermarsh]

I think I would've expected us to sort by name rather than degree.

[zmeir]

The purpose is to put on top any dependents that have the root as a direct dependent. This being the current project.

This is before sorting:

And this is after:

I will add a secondary sort by name

[charliermarsh]

Personally I think I'd prefer to sort by name -- it's a little easier to parse visually since it's predictable.

[zmeir]

Do you mean just by name or first the project and then the rest of the dependents by name?

I tried to be consistent with the output of uv pip compile.

[charliermarsh]

I was proposing sorting just by the dependent name. Doesn't uv pip compile just sort by name?

let mut dependents = graph
    .edges_directed(index, Direction::Incoming)
    .map(|edge| &graph[edge.source()])
    .map(uv_distribution_types::Name::name)
    .collect::<Vec<_>>();
dependents.sort_unstable();
dependents.dedup();
dependents

[charliermarsh]

This looks pretty reasonable overall.

[zmeir]

Thanks for your review @charliermarsh, I think this is just about ready.

I've updated the sorting as discussed here. If you would like me to change it please let me know.

I've also added a CLI option: --no-annotate, similarly to uv pip compile.

[eliasecchig]

can you consider changing the behavior so to no-annotate by default?

This is breaking many frameworks depending on uv

[charliermarsh]

Sorry, can you expand on that comment? What frameworks are depending on uv, and why are they breaking here? Comments are part of the output format.

[eliasecchig]

The default output of a uv export command changed between uv <= 0.6.10 and uv >= 0.6.11, representing a backwards-incompatible change.

I am using uv and the export command as part of a public project - see this line

 uv export --no-hashes --no-sources --no-header --no-emit-project --frozen > .requirements.txt

In short the same command:

• uv <= 0.6.10: Produces Output X
• uv >= 0.6.11: Produces Output Y

Hence why my request is to ensure --no-annotate is the default option.

[charliermarsh]

Right, but the output is still a valid requirements.txt file.

[zanieb]

Sorry, but a change in the output is not considered a breaking change if the format is unchanged. Here, we've just added comments that are compatible with the file format.

[eliasecchig]

Understood, I will deal with it on my side thanks!