Unexpected macro def

[nrc]

{
	"message": "/checkout/src/librustc_save_analysis/dump_visitor.rs:341: process_def_kind for unexpected item: Macro(DefId { krate: CrateNum(105), node: DefIndex(1) => dom_struct/5a34075aa16a3b97e60148202989464b::{{?}}[0] }, Attr)",
	"code": null,
	"level": "error: internal compiler error",
	"spans": [{
		"file_name": "/home/ncameron/servo/components/script/dom/attr.rs",
		"byte_start": 74612,
		"byte_end": 74634,
		"line_start": 15,
		"line_end": 15,
		"column_start": 5,
		"column_end": 27,
		"is_primary": true,
		"text": [{
			"text": "use dom_struct::dom_struct;",
			"highlight_start": 5,
			"highlight_end": 27
		}],
		"label": null,
		"suggested_replacement": null,
		"expansion": null
	}],
	"children": [],
	"rendered": null
}

[nrc]

Minimal test case:

bar.rs:

#![feature(proc_macro)]
extern crate proc_macro;

use proc_macro::TokenStream;
use std::str::FromStr;

#[proc_macro_attribute]
pub fn dom_struct(_args: TokenStream, input: TokenStream) -> TokenStream {
    TokenStream::from_str(&input.to_string().replace("Attr", "FooAttr")).unwrap()
}

foo.rs:

#![feature(proc_macro)]

extern crate bar;

use bar::dom_struct;

#[dom_struct]
pub struct Attr {
    f: i32,
}

fn main() {
}

[nrc]

The ICE is easy to deal, with but then that exposes a span error - a span which should show up as generated code does not.

[nrc]

rust-lang/rust#40311