Closed
Description
Step-by-step
Run cargo +nightly-2022-06-29 rustdoc -- -Z unstable-options --output-format json with this in src/lib.rs:
pub struct S;and inspect target/doc/repro.json.
Expected result
There is an item for the Error of the blanket impl impl<T, U> const TryFrom<U> for T where U: ~const Into<T> and it's default value is Infallible.
Actual
There is an item but the default value is missing. It looks like this:
"2:3121:123": {
"id": "2:3121:123",
"crate_id": 2,
"name": "Error",
"span": null,
"visibility": "default",
"docs": null,
"links": {},
"attrs": [],
"deprecation": null,
"kind": "assoc_type",
"inner": {
"generics": {
"params": [],
"where_predicates": []
},
"bounds": [],
"default": null
}
},
When using nightly-2022-06-28 instead of nightly-2022-06-29 the information about the default value is present. It looks like this:
"2:3126:123": {
"id": "2:3126:123",
"crate_id": 2,
"name": "Error",
"span": null,
"visibility": "default",
"docs": null,
"links": {},
"attrs": [],
"deprecation": null,
"kind": "typedef",
"inner": {
"type": {
"kind": "resolved_path",
"inner": {
"name": "Infallible",
"id": "2:31923:1960",
"args": {
"angle_bracketed": {
"args": [],
"bindings": []
}
},
"param_names": []
}
},
"generics": {
"params": [],
"where_predicates": []
}
}
},
This change, which in practice is a regression, is caused by #98577. But we can't revert it of course because that will result in ICEs which is even worse. So we need some kind of follow-up fix.
@rustbot labels +A-rustdoc-json +T-rustdoc +C-bug +requires-nightly