Numeric values for internally tagged enum discriminator

[jonhoo]

I'm working with a JSON type that is internally tagged with a version number. My first instinct was to write is like so:

use serde_derive::Deserialize;

#[derive(Deserialize)]
#[serde(tag = "_version")]
enum Versioned {
    #[serde(rename = "1")]
    V1 {
        works: bool,
    }
}

This works fine if the version number is represented as a string:

#[test]
fn is_str() {
    let v: Versioned = serde_json::from_str(r#"{"_version": "1", "works": true}"#).unwrap();
    assert!(matches!(v, Versioned::V1 { works: true }));
}

But fails if the version number is encoded as a number (as it indeed is in my case):

#[test]
fn is_number() {
    let v: Versioned = serde_json::from_str(r#"{"_version": 1, "works": true}"#).unwrap();
    assert!(matches!(v, Versioned::V1 { works: true }));
}

Specifically, serde_json errors (playground) with

Error("invalid type: integer `1`, expected variant identifier", line: 1, column: 14)

This feels like a bug/missing feature, in that serde should be willing to visit a number if the name of the variant is itself a string of all digits. Alternatively, I suppose I could implement my own Deserialize for this type, but that feels like overkill. Is there some other way to achieve this by sprinkling some more magical attributes?

[jonhoo]

I'm pretty sure the issue stems from somewhere deep in serde-derive around here, but I don't know enough of serde's internals to debug it properly. I think we'd need to inject a numerical visitor in here somehow, but not sure how that interacts with the collect_other_fields bit. I suppose this is really a bug in serde-derive and not in serde_json. Could this issue perhaps be moved to there by someone with permissions?