MetaItem fails to parse global paths

#[my_attr(::foo::bar)]

Does not parse as a MetaItemKind::List if the first element begins with a ::. If you remove the leading :: it parses correctly.

Triage: Can you give complete reproduction steps please? Ideally something to copy-paste into the terminal that reproduces the problem. Thanks!

I'm assuming they referred to something like:

macro_rules! accept { (#[$meta:meta]) => {}; }

accept!(#[my_attr(::foo::bar)]);

Looking at the date of submission, 2018-08-04, I first assumed that they must've used version 1.28 (released: 2018-07-30) but I couldn't repro it there. Then I randomly chose 1.25 (released: 2018-03-25) and bingo!

In 1.25, the code I've posted above fails with:

error: expected unsuffixed literal or identifier, found ::
 --> file.rs:5:19
  |
5 | accept!(#[my_attr(::foo::bar)]);
  |                   ^^

and in 1.28 and on nightly, it passes.

Next, grepping for #\[\w+\(:: in tests/ I found

tests/ui/macros/meta-item-absolute-path.rs
1:#[derive(::Absolute)] //~ ERROR failed to resolve

So we have a test for that, kinda.

We might have better tests for this but I don't want to "grep around" rn. Tentatively tagging with E-needs-test but it might not need one, needs investigation first.

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Rollup merge of rust-lang#161412 - KevinA-cpu:regression-test-53048, …

Unrolled build for #161412 in rollup 164061

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MetaItem fails to parse global paths #53048

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MetaItem fails to parse global paths #53048

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Enselic commented on Nov 16, 2023

fmease commented on Aug 15, 2025

fmease commented on Aug 15, 2025

fmease commented on Aug 16, 2025

KevinA-cpu commented on Aug 20, 2026

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