message: Consider rustc failure internal despite JSON formatting
diff: @@ -284,7 +284,7 @@ fn rustc<'a, 'cfg>(
  }
  Ok(())
  },
  - ).chain_err(|| format!("Could not compile `{}`.", name))?;
  + ).map_err(Internal::new).chain_err(|| format!("Could not compile `{}`.", name))?;
  } else if build_plan {
  state.build_plan(buildkey, rustc.clone(), outputs.clone());
  } else {
  