[ICE]: `Request to format inverted span`
Open
@aerooneqq is already working on this.
Since Aug 19, 2026.
C-bug
I-ICE
needs-triage
- Dominant language
- Rust
- Stars
- 7k
- Forks
- 1.1k
- Avg merge
- 2d 13h
- Merged PRs (30d)
- 24
Description
Code
mod non_delegatable_items { reuse impl Trait for S {}
}
Configuration
rustfmt cli options used (if applicable):
$ <rustfmt_options>
rustfmt configuration file (e.g. rustfmt.toml, if applicable):
<configuration_file>
Reproduction Steps
- rustfmt --check file.rs
Meta
rustfmt --version:
rustfmt 1.10.0-nightly (8fa1c96cfd 2026-08-17)
Error output
<output>
Backtrace
thread 'main' (3005755) panicked at src/tools/rustfmt/src/missed_spans.rs:95:9:
Request to format inverted span: /home/matthias/vcs/github/CRED/code.rs:1:32: 1:56
stack backtrace:
0: 0x7fcb3b0bf7d6 - <<std[5c30386837263582]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[a0a1658e72bc1214]::fmt::Display>::fmt
1: 0x7fcb3b80e18f - core[a0a1658e72bc1214]::fmt::write
2: 0x7fcb3b0d4dfc - <std[5c30386837263582]::sys::stdio::unix::Stderr as core[a0a1658e72bc1214]::io::write::Write>::write_fmt
3: 0x7fcb3b092a6a - std[5c30386837263582]::panicking::default_hook::{closure#0}
4: 0x7fcb3b0b3a83 - std[5c30386837263582]::panicking::default_hook
5: 0x7fcb3a03782a - std[5c30386837263582]::panicking::update_hook::<alloc[4a2b879cc634dc41]::boxed::Box<rustc_driver_impl[291a57e7636f8807]::install_ice_hook::{closure#1}>>::{closure#0}
6: 0x7fcb3b0b3f22 - std[5c30386837263582]::panicking::panic_with_hook
7: 0x7fcb3b092b22 - std[5c30386837263582]::panicking::panic_handler::{closure#0}
8: 0x7fcb3b08b9e9 - std[5c30386837263582]::sys::backtrace::__rust_end_short_backtrace::<std[5c30386837263582]::panicking::panic_handler::{closure#0}, !>
9: 0x7fcb3b09452d - __rustc[8ce9b7f39dcd8887]::rust_begin_unwind
10: 0x7fcb37d5430c - core[a0a1658e72bc1214]::panicking::panic_fmt
11: 0x559fc712e63f - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::format_missing_indent
12: 0x559fc70f370c - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_assoc_item
13: 0x559fc70fa182 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_impl_items
14: 0x559fc7083d7a - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::with_context::<core[a0a1658e72bc1214]::result::Result<alloc[4a2b879cc634dc41]::string::String, rustfmt_nightly[15a900bfe66b42a0]::rewrite::RewriteError>, <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_item::{closure#0}>
15: 0x559fc70ee09c - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_item
16: 0x559fc7136ec6 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_items_with_reordering
17: 0x559fc70f3070 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::walk_mod_items
18: 0x559fc70edd01 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_item
19: 0x559fc7136ec6 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::visit_items_with_reordering
20: 0x559fc70f3070 - <rustfmt_nightly[15a900bfe66b42a0]::visitor::FmtVisitor>::walk_mod_items
21: 0x559fc70674fa - <scoped_tls[67b73826a82c6420]::ScopedKey<rustc_span[66c93350f36606f3]::SessionGlobals>>::with::<<rustfmt_nightly[15a900bfe66b42a0]::Session<std[5c30386837263582]::io::stdio::Stdout>>::format_input_inner::{closure#0}, core[a0a1658e72bc1214]::result::Result<rustfmt_nightly[15a900bfe66b42a0]::FormatReport, rustfmt_nightly[15a900bfe66b42a0]::ErrorKind>>
22: 0x559fc706167f - rustfmt[917e195e023d768e]::format_and_emit_report::<std[5c30386837263582]::io::stdio::Stdout>
23: 0x559fc7076c9e - rustfmt[917e195e023d768e]::execute
24: 0x559fc707203a - rustfmt[917e195e023d768e]::main
25: 0x559fc70702eb - std[5c30386837263582]::sys::backtrace::__rust_begin_short_backtrace::<fn(), ()>
26: 0x559fc7070ae9 - std[5c30386837263582]::rt::lang_start::<()>::{closure#0}
27: 0x7fcb3cad8bd4 - std[5c30386837263582]::rt::lang_start_internal
28: 0x559fc7081138 - main
29: 0x7fcb35e27741 - <unknown>
30: 0x7fcb35e27879 - __libc_start_main
31: 0x559fc6f5e5c9 - <unknown>
32: 0x0 - <unknown>
error: the compiler unexpectedly panicked. This is a bug
note: we would appreciate a bug report: https://github.com/rust-lang/rustfmt/issues/new?labels=bug
note: please make sure that you have updated to the latest nightly
note: please attach the file at `/home/matthias/vcs/github/CRED/rustc-ice-2026-08-18T18_29_00-3005755.txt` to your bug report
note: rustc 1.100.0-nightly (8fa1c96cf 2026-08-17) running on x86_64-unknown-linux-gnu
query stack during panic:
end of query stack
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Assessment
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