Running cargo clippy on the crates.io codebase, I'm running into an ICE that appears to be fixed by this clippy commit: fix ice when checking rustc libstd · rust-lang/rust-clippy@572c405 · GitHub
I'm seeing the same failure on rustc 1.53.0-beta.12 (e7a67cc91 2021-06-12). The issue is resolved on nightly.
thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', src/tools/clippy/clippy_lints/src/matches.rs:1595:53
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-clippy/issues/new
note: Clippy version: clippy 0.1.53 (dbe03e2 2021-06-15)
query stack during panic:
#0 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `cargo-registry`