Bug: `internal error: unreachable code: ...`

[kaspar030]

Describe the bug

Our CI fails with this on some PRs:

Run cargo binstall --no-confirm --no-discover-github-token --force cargo-deny
 INFO resolve: Resolving package: 'cargo-deny'
 WARN The package cargo-deny v0.16.1 (x86_64-unknown-linux-musl) has been downloaded from github.com
 INFO This will install the following binaries:
 INFO   - cargo-deny (cargo-deny -> /home/runner/.cargo/bin/cargo-deny)
 INFO Installing binaries...
 INFO Done in 1.886941248s
thread '<unnamed>' panicked at /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/krates-0.17.1/src/builder.rs:718:25:
internal error: entered unreachable code: unable to locate defmt-03 for crate registry+https://github.com/rust-lang/crates.io-index#embedded-hal@0.2.7 features(["unproven"])
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: Process completed with exit code 101.

embedded-hal 0.2.7 indeed doesn't have the defmt-03 feature. embedded-hal 1.0 has, and IIUC both are used at the same time in this case.

To reproduce

I can reproduce quickly on our repo:

git clone https://github.com/ROMemories/RIOT-rs -b feat/spi-main-abstraction
cd RIOT-rs
cargo deny check bans licenses sources

cargo-deny version

v0.16.1

What OS were you running cargo-deny on?

Linux

Additional context

No response