itertool's chunk iterator causes a compiler panic when mapping with non-lexical lifetimes

[Jess3Jane]

This is the minimum example I was able to get it down to:

#![feature(nll)]

extern crate itertools;
use itertools::Itertools;

fn main() {
    b"abcdefg".iter().chunks(2).into_iter().map(|a| 1);
}

When try to compile this the compiler says

thread 'main' panicked at 'scrape_region_constraints: incoming region obligations = [
    (
        NodeId(
            20
        ),
        RegionObligation(sub_region='_#1r, sup_type=&u8)
    )
]', librustc/traits/query/type_op/custom.rs:85:5

It is specifically an issue with map and non-lexical lifetimes as removing either of them doesn't cause the bug.

Meta

My current rust version is

rustc 1.30.0-nightly (63d66494a 2018-08-23)
binary: rustc
commit-hash: 63d66494aff57411bfec1dd2a3a5f1af900feab6
commit-date: 2018-08-23
host: x86_64-unknown-linux-gnu
release: 1.30.0-nightly
LLVM version: 7.0

But this happened on every other system I tried it on, including play.rust-lang.org

[memoryruins]

Thanks for the minimum example!
Similar issues: #53482 #52992
Potential fix: #53580

[nikomatsakis]

I can confirm that this is fixed by #53580