Fail to deserialize `RelativePathBuf` in a enum

[BobAnkh]

Hello, thank you for your work! Figment is really an awesome work with ergonomic designs.

But I encounter some problems when I would like to deserialize a struct with RelativePathBuf as its field, which is inside an enum:

#[derive(Serialize, Deserialize, Debug)]
pub struct Test {
    trace: RelativePathBuf,
}

#[derive(Serialize, Deserialize, Debug)]
#[serde(tag = "tp")]
pub enum Mode {
    Test(Test),
}

I'm using the following code to extract the enum:

fn main() {
    let m = figment::Figment::new().merge(Toml::file("./mode.toml")).extract::<Mode>().unwrap();
}

Inside the mode.toml file is:

tp = "Test"
trace = "./123.json"

This will result in an error:

called `Result::unwrap()` on an `Err` value: Error { tag: Tag::Default, profile: None, metadata: None, path: [], kind: InvalidType(Str("./123.json"), "struct RelativePathBuf"), prev: None }

If I change the RelativePathBuf to String, then it works.

It also works if I directly deserialize the struct Test with its field type still as RelativePathBuf, e.g. with:

fn main(){
    let t = figment::Figment::new().merge(Toml::file("./test.toml")).extract::<Test>().unwrap();
}

and in the test.toml:

trace = "./123.json"

I'm wondering if there is a way to fix my problem, or is this behavior intended?

---

The deps I'm using:

[dependencies]
figment = { version = "0.10.19", features = ["toml", "json"] }
serde = { version = "1.0.203", features = ["derive"] }
toml = "0.8.14"