impl Error on Enum with str type

[adjivas]

Hello, I repport this issue.

I tried this code:

use std::fmt;
use std::fmt::{Display, Debug};

use std::error::Error;

enum PartError {
    UnknownPart(str),
    ForbiddenGlyph(char),
}

impl Error for PartError {
    fn description(&self) -> &str {
        match *self {
            PartError::UnknownPart(_) => "the name of part is unknown",
            PartError::ForbiddenGlyph(_) => "the glyph is on a forbidden range",
        }
    }
}

impl Display for PartError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self)
    }
}

impl Debug for PartError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self)
    }
}

fn main() {
}

I expected to see this happen:

error: internal compiler error: ../src/librustc_trans/type_of.rs:178: Unexpected tail in unsized_info_ty: PartError for ty=PartError

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

thread 'rustc' panicked at 'Box<Any>', ../src/librustc_errors/lib.rs:634
note: Run with `RUST_BACKTRACE=1` for a backtrace.

[apasel422]

Thanks for the report! Closing as duplicate of #16812.