Crash when running license check with Rust 1.47.0

[cberner]

Describe the bug
cargo deny check licenses fails with Rust 1.47.0

To Reproduce
Steps to reproduce the behavior:

1. git clone https://github.com/fleetfs/fleetfs
2. cd fleetfs && git checkout 80cc4212e79a5e38dff8c8e2b118bcc8eee3fa09
3. rustup override set 1.47.0
4. cargo deny check licenses

thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: 21', /home/cberner/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/krates-0.2.0/src/builder.rs:543:87
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Expected behavior
No error, as observed when using rustup override set 1.46.0

Device:

• OS: Ubuntu 20.04

[Jake-Shadle]

Thanks for the report! This is resolved, I just need to cut a release of cargo-deny (hopefully today?), but if you want to work around this in the meantime, you can use the rev = <commit-sha> specifier instead of the branch = <branch_name> specifier.