Initiated a project with axum and made no changes.

... required by package `axum v0.6.10`
    ... which satisfies dependency `axum = "^0.6.10"` of package `proj v0.1.0 (/Users/xxxxxx.xxxxxx/Desktop/xxxxxx/yyy/proj)`
versions that meet the requirements `^1.25.0` are: 1.26.0, 1.25.0

all possible versions conflict with previously selected packages.

  previously selected package `tokio v1.22.0`
    ... which satisfies dependency `tokio = "=1.22.0"` of package `shuttle-service v0.11.0`
    ... which satisfies dependency `shuttle-service = "^0.11.0"` of package `proj v0.1.0 (/Users/xxxxxx.xxxxxx/Desktop/xxxxxx/yyy/proj)`

failed to select a version for `tokio` which could resolve this conflict

my axum is currently on 6.1 and works - maybe try a downgrade?

Looks like you are using a higher version of tokio than 1.22, try

tokio = "1"

in your project, so that cargo can choose an optimal version

tokio pinning is still an issue at the moment but there should be some changes coming at some point

downgrading axum to 0.6.1 works.

I checked their dependencies. Axum 0.6.10 went from tokio 1.21 -> 1.25, which makes it incompatible with shuttle atm. So go for 0.6.9 🙂

it looks like this is already a known issue on gh but I've let the engineering team know this is starting to become slightly more common

another n=1 data point: I also encountered this today (when creating a new axum project w/ shuttle), and this thread helped troubleshoot and solve by downgrading the version 👌