rustc ICE: "region_obligations not empty"

[alecmocatta]

On current nightly:

   Compiling deploy v0.1.0
thread 'main' panicked at 'region_obligations not empty: [
    (
        NodeId(
            17744
        ),
        RegionObligation(sub_region='_#1r, sup_type=T1)
    )
]', librustc/infer/mod.rs:1057:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.

error: internal compiler error: unexpected panic

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 1.28.0-nightly (01cc982e9 2018-06-24) running on x86_64-unknown-linux-gnu

note: compiler flags: -C opt-level=3 --crate-type lib

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

Rust issue here: rust-lang/rust#51649.

./rust-toolchain is a known working rustc version in the interim.

[alecmocatta]

Fixed in rustc, see aforelinked issue rust-lang/rust#51649