Regression: The crate named `assert-cmp` v0.2.1 no longer compile on Rust 1.87.0

[KSXGitHub]

I tried this code:

[dependencies]
assert-cmp = "0.2.1"

fn main() {
    assert_cmp::assert_op!(0 < 1);
}

I expected to see this happen: Compile successfully

Instead, this happened: Error

error: expected one of `!`, `.`, `;`, `?`, `{`, `}`, or an operator, found `::`
 --> src/main.rs:2:5
  |
2 |     assert_cmp::assert_op!(0 < 1);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected one of 7 possible tokens
  |
  = note: this error originates in the macro `assert_cmp::assert_op` (in Nightly builds, run with -Z macro-backtrace for more info)

Meta

rustc --version --verbose:

rustc 1.87.0 (17067e9ac 2025-05-09)
binary: rustc
commit-hash: 17067e9ac6d7ecb70e50f92c1944e545188d2359
commit-date: 2025-05-09
host: x86_64-unknown-linux-gnu
release: 1.87.0
LLVM version: 20.1.1

Backtrace

error: expected one of `!`, `.`, `;`, `?`, `{`, `}`, or an operator, found `::`
 --> src/main.rs:2:5
  |
2 |     assert_cmp::assert_op!(0 < 1);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected one of 7 possible tokens
  |
  = note: this error originates in the macro `assert_cmp::assert_op` (in Nightly builds, run with -Z macro-backtrace for more info)

error: could not compile `debug-assert-op` (bin "debug-assert-op") due to 1 previous error

[theemathas]

Duplicate of #140223

[apiraino]

Yes, this was a breaking change mentioned in the changelog
https://github.com/rust-lang/rust/releases/tag/1.87.0

so the assert-cmp crate seems to have fixed that in the latest release. With v0.3.0 the issue does not occur.

[KSXGitHub]

so the assert-cmp crate seems to have fixed that in the latest release. With v0.3.0 the issue does not occur.

It would have been fixed sooner if I was notified of it. You guys ran crater, knew which crates break, but did not notify the library authors.

[workingjubilee]

Apologies. @nnethercote triaged the crater run. There were a little under 20 key regressions, and yours did come up by name amongst them. We do not have a policy of mandatory notifications to affected crates, and we have no infra to make it easy, so it would have involved manual labor to notify each author. Perhaps we could add that infrastructure to crates.io for maintainers who wish to opt-in to notifications about crater regressions.