ICE: Assert at src/librustc_middle/ty/query/on_disk_cache.rs:491:5 - Uncertain of cause (unreproducable)

[AldaronLau]

ICE when running cargo build. Running cargo clean makes the ICE go away.

I tried this code: https://github.com/libcala/stick/

git checkout c62fba3ab591d77177a5de4c36493ce8ecbb487b

Previous commands

I don't know how helpful this is, considering that I can't reproduce now that I have ran cargo clean, even though I was able to reproduce the error before.

cargo tree
cargo run --example readme --release
git diff
tig
ls pad_db/pad/mapping/
cargo doc --open

Meta

RUST_BACKTRACE=1 cargo build --verbose:

Backtrace:

   Fresh unicode-xid v0.2.0
   Fresh smelling_salts v0.1.0
   Fresh proc-macro2 v1.0.18
   Fresh quote v1.0.6
   Fresh serde v1.0.111
   Fresh syn v1.0.30
   Fresh toml v0.5.6
   Fresh serde_derive v1.0.111

Compiling stick v0.9.0 (/home/aldaronlau/devel/stick)
Running rustc --crate-name stick --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 --cfg 'feature="default"' -C metadata=1889ceb89eb5ce80 -C extra-filename=-1889ceb89eb5ce80 --out-dir /home/aldaronlau/devel/stick/target/debug/deps -C incremental=/home/aldaronlau/devel/stick/target/debug/incremental -L dependency=/home/aldaronlau/devel/stick/target/debug/deps --extern smelling_salts=/home/aldaronlau/devel/stick/target/debug/deps/libsmelling_salts-51ee0fa6c978ca0c.rmeta
warning: unnecessary parentheses around assigned value
--> src/ffi/linux.rs:771:20
|
771 | let norm = (range * 0.5);
| ^^^^^^^^^^^^^ help: remove these parentheses
|
= note: #[warn(unused_parens)] on by default

thread 'rustc' panicked at 'assertion failed: (left == right)
left: 7505659740231074721,
right: 1002111927320821928687967599834759150', src/librustc_middle/ty/query/on_disk_cache.rs:491:5
stack backtrace:
0: backtrace::backtrace::libunwind::trace
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
1: backtrace::backtrace::trace_unsynchronized
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
2: std::sys_common::backtrace::_print_fmt
at src/libstd/sys_common/backtrace.rs:78
3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
at src/libstd/sys_common/backtrace.rs:59
4: core::fmt::write
at src/libcore/fmt/mod.rs:1069
5: std::io::Write::write_fmt
at src/libstd/io/mod.rs:1504
6: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:62
7: std::sys_common::backtrace::print
at src/libstd/sys_common/backtrace.rs:49
8: std::panicking::default_hook::{{closure}}
at src/libstd/panicking.rs:198
9: std::panicking::default_hook
at src/libstd/panicking.rs:218
10: rustc_driver::report_ice
11: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:515
12: rust_begin_unwind
at src/libstd/panicking.rs:419
13: std::panicking::begin_panic_fmt
at src/libstd/panicking.rs:373
14: rustc_middle::ty::query::on_disk_cache::OnDiskCache::new
15: rustc_incremental::persist::load::load_query_result_cache
16: rustc_interface::passes::create_global_ctxt
17: rustc_interface::queries::Queries::global_ctxt
18: rustc_interface::interface::run_compiler_in_existing_thread_pool
19: scoped_tls::ScopedKey::set
20: rustc_ast::attr::with_globals
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 (49cae55 2020-06-01) running on x86_64-unknown-linux-gnu

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

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

query stack during panic:
end of query stack
warning: 1 warning emitted

error: could not compile stick.

Caused by:
process didn't exit successfully: rustc --crate-name stick --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 --cfg 'feature="default"' -C metadata=1889ceb89eb5ce80 -C extra-filename=-1889ceb89eb5ce80 --out-dir /home/aldaronlau/devel/stick/target/debug/deps -C incremental=/home/aldaronlau/devel/stick/target/debug/incremental -L dependency=/home/aldaronlau/devel/stick/target/debug/deps --extern smelling_salts=/home/aldaronlau/devel/stick/target/debug/deps/libsmelling_salts-51ee0fa6c978ca0c.rmeta (exit code: 101)

[Enselic]

Triage: Without a way to reproduce, there is not much that can be done. Feel free to reopen if a way to reproduce is found.

[saethlin]

As far as I can tell, the ICE reported in this issue is caused by another process damaging rustc's build artifacts or by a buggy filesystem. That other process could be anything from an IDE running the compiler at the same time as a manual build to a find-and-replace that accidentally edits files in the target directory.

#124686 contains a mitigation for this situation; the compiler now has a crude way to detect and ignore damaged incremental compilation files. You will still get a warning about the damaged file, but the build should proceed normally. That change shipped in Rust 1.80 which released today, so I am closing this issue and a few others which as far as I can tell all have the same root cause. You shouldn't see this ICE anymore, but please file a new issue if you see something like it on 1.80 or later.