Use the same version of a transitive dependency

[oriongonza]

Problem

Let's say that I'm using

[dependencies]
reqwest = "0.12.5"
axum = "0.7.5"

But I also want to add tokio as a direct dependency, and I want to match the version that axum uses.
Specifying * as the version could choose either.

Proposed Solution

Something like this

[dependencies]
reqwest = "0.12.5"
axum = "0.7.5"
tokio = "axum"

Notes

No response

[epage]

Blocked on rust-lang/rust#44663

As specified, this makes an implementation detail part of a crate's API and would be beholden to semver. A way to solve that is with public/private dependencies. A similar idea was proposed in the RFC. It did require explicitly specify the dependency relationship.

Another approach also came up on Mastadon recently

@alice_i_cecile I’ve started using cargo’s feature:

wgpu.workspace = true

Which is very cool for only having to change things in one place when you have multiple crates.

I really wish you could do something like this though:

wgpu = "bevy_render.wgpu"

So you don’t even have to change that one place.

For the full thread, see https://aus.social/@bnut/112832056643395623