regression: ICE all spans must be disjoint

[BoxyUwU]

• https://crater-reports.s3.amazonaws.com/beta-1.91-2/beta-2025-09-21/gh/WasmSanitizer.WasmSanitizer/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.91-2/beta-2025-09-21/reg/abi_stable_derive_lib-0.6.2/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.91-2/beta-2025-09-21/reg/bittwiddler-0.0.2/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.91-2/beta-2025-09-21/reg/pest-deconstruct-derive-0.2.0/log.txt

[INFO] [stderr] thread 'rustc' (357) panicked at compiler/rustc_errors/src/lib.rs:385:17:
[INFO] [stderr] assertion `left == right` failed: all spans must be disjoint

[madsmtm]

Probably fixed by #147849 (?)

CC @jdonszelmann

[jdonszelmann]

Yea, but that's still in mcp phase

[theemathas]

Presumably regressed in #146121. cc @Muscraft

The for_loops_over_fallibles lint had a preexisting bug. It produced an invalid suggestion on stable. This invalid suggestion was caught in an assert in the aforementioned PR.

Output on stable:

[INFO] [stderr] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stderr]   --> lib/wasm/binary_derive/src/lib.rs:37:13
[INFO] [stderr]    |
[INFO] [stderr] 37 | /             quote!({
[INFO] [stderr] 38 | |                 #( #check_tag )*
[INFO] [stderr] 39 | |                 #decode_fields
[INFO] [stderr] 40 | |             })
[INFO] [stderr]    | |______________^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stderr] help: to check pattern in a loop use `while let`
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/quote-0.4.2/src/lib.rs:379:29
[INFO] [stderr]    |
[INFO] [stderr] 379~         nested_tuples_pat!((while let Some(for pounded_var_names!(nested_tuples_pat () $($inner)*)
[INFO] [stderr] 380~         nested_tuples_pat!(() = ) $($rest)*)
[INFO] [stderr]    |
[INFO] [stderr] help: consider using `if let` to clear intent
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/quote-0.4.2/src/lib.rs:379:29
[INFO] [stderr]    |
[INFO] [stderr] 379~         nested_tuples_pat!((if let Some(for pounded_var_names!(nested_tuples_pat () $($inner)*)
[INFO] [stderr] 380~         nested_tuples_pat!(() = ) $($rest)*)

[theemathas]

Minimized-ish reproduction:

use quote::*;

fn main() {
    let name = Some(quote! { a });
    let translation = "a";
    let _ = quote!(#(#name:)* #translation);
}

[package]
name = "repro"
version = "0.1.0"
edition = "2024"

[dependencies]
quote = "0.4"

[theemathas]

Minimized reproduction:

src/main.rs

fn main() {
    let _name = Some(1);
    dep::do_loop!(_name);
}

dep/src/lib.rs

#[macro_export]
macro_rules! identity {
    ($x:ident) => {
        $x
    };
}

#[macro_export]
macro_rules! do_loop {
    ($x:ident) => {
        for $crate::identity!($x) in $x {}
    };
}

Zip of all files needed for reproduction, for your convenience: repro.zip