--pretty expanded produces a compiler error

[wycats]

✗ rustc --pretty expanded commands/cargo-read-manifest/main.rs -L target/libs
#[crate_id = "cargo-read-manifest"];
use std::prelude::*;
extern crate std = "std#0.10-pre";
extern crate green = "green#0.10-pre";
extern crate rustuv = "rustuv#0.10-pre";

extern crate hammer;
extern crate serialize;
extern crate toml;
extern crate semver;

use hammer::{FlagDecoder, FlagConfig, FlagConfiguration};
use serialize::{Decoder, Decodable};
use serialize::json::Encoder;
use toml::from_toml;
use semver::Version;

#[deriving(Decodable, Encodable)]
struct Manifest {
    project: ~Project,
}
#[doc = "Automatically derived."]
impl <__E: ::serialize::Encoder> ::serialize::Encodable<__E> for Manifest {
    fn encode(&self, __arg_0: &mut __E) {
        match *self {
            Manifest{project: ref __self_0_0} =>
error: internal compiler error: unexpected failure
This message reflects a bug in the Rust compiler.
We would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: the compiler hit an unexpected failure path. this is a bug
Ok(task 'rustc' failed at 'assertion failed: body.stmts.is_empty()', /Users/engineering/Code/oss/rust/src/libsyntax/print/pprust.rs:1383
)

This is the original source file: https://gist.github.com/anonymous/1d6e158db126725eeb2d

[huonw]

Dupe of #12685.