Rust: failed to find a workspace root for workspace dependency in a non-workspace crate

[Jefffrey]

Is there an existing issue for this?

• I have searched the existing issues

Package ecosystem

cargo

Package manager version

1.77

Language version

1.77

Manifest location and content before the Dependabot update

No response

dependabot.yml content

https://github.com/apache/arrow-datafusion/blob/b2f5e39c4636951ccb7357478f21fcf34a692f51/.github/dependabot.yml

Updated dependency

No response

What you expected to see, versus what you actually saw

We have a repository with a workspace (datafusion):

https://github.com/apache/arrow-datafusion/blob/b2f5e39c4636951ccb7357478f21fcf34a692f51/Cargo.toml#L18-L43

However we have a nested crate which is excluded from the workspace:

https://github.com/apache/arrow-datafusion/blob/b2f5e39c4636951ccb7357478f21fcf34a692f51/datafusion-cli/Cargo.toml

This nested crate (datafusion-cli) has a dependency on datafusion. We are getting this error when trying to setup dependabot for datafusion-cli:

 Dependabot can't resolve your Rust dependency files

Dependabot failed to update your dependencies because there was an error resolving your Rust dependency files.

Dependabot encountered the following error:

Updating crates.io index
error: failed to get `datafusion` as a dependency of package `datafusion-cli v37.0.0 (dependabot_tmp_dir/datafusion-cli)`

Caused by:
  failed to load source for dependency `datafusion`

Caused by:
  Unable to update dependabot_tmp_dir/datafusion/core

Caused by:
  failed to parse manifest at `dependabot_tmp_dir/datafusion/core/Cargo.toml`

Caused by:
  error inheriting `version` from workspace root manifest's `workspace.package.version`

Caused by:
  failed to find a workspace root

Usually to build/check/run datafusion-cli we would cd into the datafusion-cli/ dir and run the cargo commands there, and that would work to build and resolve dependencies just fine.

Native package manager behavior

No response

Images of the diff or a link to the PR, issue, or logs

No response

Smallest manifest that reproduces the issue

No response