cargo doc => thread 'rustc' panicks with "byte index 2 is not a char boundary ..." on nightly

[lrieb]

Code

The error only appears on nightly.

steps to reproduce:

cargo init                    # or cargo init --lib
cargo add axum       # this crate caused the error
cargo doc

rustc --version --verbose:

rustc 1.74.0-nightly (ef85656a1 2023-08-21)
binary: rustc
commit-hash: ef85656a10657ba5e4f7fe2931a4ca6293138d51
commit-date: 2023-08-21
host: x86_64-unknown-linux-gnu
release: 1.74.0-nightly
LLVM version: 17.0.0

cargo version --verbose

cargo 1.74.0-nightly (80eca0e58 2023-08-19)
release: 1.74.0-nightly
commit-hash: 80eca0e58fb2ff52c1e94fc191b55b37ed73e0e4
commit-date: 2023-08-19
host: x86_64-unknown-linux-gnu
libgit2: 1.6.4 (sys:0.17.2 vendored)
libcurl: 8.2.1-DEV (sys:0.4.65+curl-8.2.1 vendored ssl:OpenSSL/1.1.1u)
ssl: OpenSSL 1.1.1u  30 May 2023
os: Fedora 37.0.0 [64-bit]

Error output

Documenting axum v0.6.20
thread 'rustc' panicked at src/librustdoc/passes/collect_intra_doc_links.rs:1446:33:
byte index 2 is not a char boundary; it is inside '“' (bytes 0..3) of `“extractors”`
stack backtrace:
   0: rust_begin_unwind
             at /rustc/ef85656a10657ba5e4f7fe2931a4ca6293138d51/library/std/src/panicking.rs:617:5
   1: core::panicking::panic_fmt
             at /rustc/ef85656a10657ba5e4f7fe2931a4ca6293138d51/library/core/src/panicking.rs:67:14
   2: core::str::slice_error_fail_rt
   3: core::str::slice_error_fail
             at /rustc/ef85656a10657ba5e4f7fe2931a4ca6293138d51/library/core/src/str/mod.rs:87:9
   4: <rustdoc::passes::collect_intra_doc_links::LinkCollector>::resolve_links
   5: rustdoc::passes::collect_intra_doc_links::collect_intra_doc_links
   6: <rustc_session::session::Session>::time::<(rustdoc::clean::types::Crate, rustdoc::config::RenderOptions, rustdoc::formats::cache::Cache), rustdoc::main_args::{closure#1}::{closure#0}::{closure#0}::{closure#0}>
   7: <rustc_middle::ty::context::GlobalCtxt>::enter::<rustdoc::main_args::{closure#1}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
   8: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustdoc::main_args::{closure#1}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md

note: please attach the file at `/home/luk/.cargo/registry/src/index.crates.io-6f17d22bba15001f/axum-0.6.20/rustc-ice-2023-08-22T21:28:21.787458591Z-17768.txt` to your bug report

note: compiler flags: --crate-type lib

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

query stack during panic:
end of query stack
error: could not document `axum`

Caused by:
  process didn't exit successfully: `/home/luk/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustdoc --edition=2021 --crate-type lib --crate-name axum /home/luk/.cargo/registry/src/index.crates.io-6f17d22bba15001f/axum-0.6.20/src/lib.rs --cap-lints allow -o /home/luk/code/target/doc --cfg 'feature="default"' --cfg 'feature="form"' --cfg 'feature="http1"' --cfg 'feature="json"' --cfg 'feature="matched-path"' --cfg 'feature="original-uri"' --cfg 'feature="query"' --cfg 'feature="tokio"' --cfg 'feature="tower-log"' --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=174 -C metadata=6a2b919d3caa327b -L dependency=/home/luk/code/target/debug/deps --extern async_trait=/home/luk/code/target/debug/deps/libasync_trait-09449879fe59171c.so --extern axum_core=/home/luk/code/target/debug/deps/libaxum_core-be3802c8acc62418.rmeta --extern bitflags=/home/luk/code/target/debug/deps/libbitflags-17eaae058c49a1b8.rmeta --extern bytes=/home/luk/code/target/debug/deps/libbytes-b51fc775aa196866.rmeta --extern futures_util=/home/luk/code/target/debug/deps/libfutures_util-181be8ad31767cdd.rmeta --extern http=/home/luk/code/target/debug/deps/libhttp-777d680c671caa21.rmeta --extern http_body=/home/luk/code/target/debug/deps/libhttp_body-3675ad811d3791f2.rmeta --extern hyper=/home/luk/code/target/debug/deps/libhyper-26f28c600bdc1ee2.rmeta --extern itoa=/home/luk/code/target/debug/deps/libitoa-94c3240fd22fdaed.rmeta --extern matchit=/home/luk/code/target/debug/deps/libmatchit-82c8078bb1278ab5.rmeta --extern memchr=/home/luk/code/target/debug/deps/libmemchr-3693a015842dadb3.rmeta --extern mime=/home/luk/code/target/debug/deps/libmime-d49ab82920264418.rmeta --extern percent_encoding=/home/luk/code/target/debug/deps/libpercent_encoding-82f182e7e48872ba.rmeta --extern pin_project_lite=/home/luk/code/target/debug/deps/libpin_project_lite-57b44a4b14a3bb39.rmeta --extern serde=/home/luk/code/target/debug/deps/libserde-0d5b7588f54bc67d.rmeta --extern serde_json=/home/luk/code/target/debug/deps/libserde_json-278584084946d9dc.rmeta --extern serde_path_to_error=/home/luk/code/target/debug/deps/libserde_path_to_error-39acfc136a848aca.rmeta --extern serde_urlencoded=/home/luk/code/target/debug/deps/libserde_urlencoded-e540d2bfed2238c6.rmeta --extern sync_wrapper=/home/luk/code/target/debug/deps/libsync_wrapper-1f9c28405a3b7050.rmeta --extern tokio=/home/luk/code/target/debug/deps/libtokio-6e8d9240e9f399fd.rmeta --extern tower=/home/luk/code/target/debug/deps/libtower-3058a136415171e6.rmeta --extern tower_layer=/home/luk/code/target/debug/deps/libtower_layer-e590ca43fcd1237b.rmeta --extern tower_service=/home/luk/code/target/debug/deps/libtower_service-6e838e2bbdb7ccf9.rmeta --crate-version 0.6.20 --cfg nightly_error_messages` (exit status: 101)

rustc-ice-2023-08-22T21:28:21.787458591Z-17768.txt

[lrieb]

I believe this might already be fixed by #115070

[notriddle]

Yep, I tested with the branch. It's fixed.

[notriddle]

Duplicate of #115062