Investigate why clippy chokes on the repo

[Ryman]

cargo +nightly install clippy && cargo +nightly clippy

error: internal compiler error: librustc/ty/context.rs:503: node_id_to_type: no type for node `expr 10 (id=678)`

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:542:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.
error: aborting due to previous error


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

note: rustc 1.27.0-nightly (ad610bed8 2018-04-11) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 --crate-type lib

note: some of the compiler flags provided by cargo are hidden

error: Could not compile `hyper`.