Weird cyclic dependency case

[mikhailOK]

Cyclic dependencies through dev-dependencies can lead to a confusing error message

Here is a minimal repro: https://github.com/mikhailOK/bad-cargo-cyclic-dependency

Two crates, crate1 and crate2
crate2 depends on crate1, but crate1 has crate2 in [dev-dependencies]

crate1/src/lib.rs:

#[derive(PartialEq, Eq, Debug)]
pub struct Value {}

pub struct ValueReturner {}

impl ValueReturner {
    pub fn return_value(&self) -> Value {
        Value {}
    }
}

#[cfg(test)]
mod tests {
    pub fn mismatched_types() {
        let returner = crate2::get_returner();
        assert_eq!(returner.return_value(), crate::Value {});
    }
}

crate2/src/lib.rs:

use crate1::ValueReturner;

pub fn get_returner() -> ValueReturner {
    ValueReturner {}
}

cargo test -p crate1 fails with a compilation error:

error[E0308]: mismatched types
  --> crate1/src/lib.rs:16:9
   |
16 |         assert_eq!(returner.return_value(), crate::Value {});
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `crate1::Value`, found struct `Value`
   |
   = note: expected type `crate1::Value`
              found type `Value`

Comipler version: rustc 1.35.0-nightly (e68bf8ae1 2019-03-11)

My question is, is there a valid use case for this kind of cyclic dependencies?

[kaichaosun]

I have the same issue, and asking some help here.