Rust provider tries to open Cargo.toml in wrong folder

[prideout]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I have a cargo workspace and nixpacks plan . or nixpacks build . both say:

Error reading crates/apollo-core/src/Cargo.toml

In my workspace, there's no Cargo.toml in any src/. There's one at the workspace root and one in crate root. My workspace structure looks like:

.
├── Cargo.lock
├── Cargo.toml
├── crates
│   ├── apollo-core
│   │   ├── Cargo.toml
│   │   └── src
│   │       └── lib.rs
│   ├── rest-server
│   │   ├── Cargo.toml
│   │   └── src
│   │       └── main.rs
│   └── wasm-connectors
│       ├── Cargo.toml
│       └── src
│           └── lib.rs
├── nixpacks.toml
└── rustfmt.toml

To reproduce

Create a Rust workspace using a structure as described in the bug report and do nixpacks plan . This fails.

As an experiment I tried nixpacks plan ./crates/rest-server, which succeeds, but produces the wrong plan because cargo doesn't know it's inside a workspace. The actual build fails.

Expected behavior

No response

Environment

macOS. nixpacks 1.21.3