ICE when compiling or checking docopt crate

[alexander-jackson]

Updated to the latest nightly compiler and did a fresh compile of one of my projects, which failed with this error when processing docopt. Minimal working example exists of just docopt in the Cargo.toml.

Code

fn main() {
    println!("Hello, world!");
}

Cargo.toml

[package]
name = "blank"
version = "0.1.0"
authors = ["Alexander Jackson <[email protected]>"]
edition = "2018"

[dependencies]
docopt = "1"

Meta

rustc --version --verbose:

rustc 1.44.0-nightly (f509b26a7 2020-03-18)
binary: rustc
commit-hash: f509b26a7730d721ef87423a72b3fdf8724b4afa
commit-date: 2020-03-18
host: x86_64-apple-darwin
release: 1.44.0-nightly
LLVM version: 9.0

Error output

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/librustc/hir/mod.rs:81:37
note: run with `RUST_BACKTRACE=1` environment variable to display 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 1.44.0-nightly (f509b26a7 2020-03-18) running on x86_64-apple-darwin

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

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

error: could not compile `docopt`.

Backtrace

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/librustc/hir/mod.rs:81:37
stack backtrace:
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note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose 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 1.44.0-nightly (f509b26a7 2020-03-18) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [hir_owner] processing `regex`
#1 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `docopt`.

[jonas-schievink]

duplicate of #70041