Unconstrained function call only fails when input is constant

[michaeljklein]

pub unconstrained fn foo(input: Field) -> Field {
    // moving the `!= 0` from `bar` to here fixes the panic:
    (input == 0) as Field
}

pub fn bar(input: Field) {
    // Safety: test
    let output = unsafe { foo(input) };

    // removing the empty assert message fixes the panic:
    assert(output != 0, "");
}

mod test {
    use crate::bar;

    // this panics:
    #[test]
    fn test_local() {
        bar(0);
    }

    global x_global: Field = 0;

    // this panics:
    #[test]
    fn test_global() {
        bar(x_global);
    }

}

// it works when calling or inlining `bar` in `main` (with `input = 0`)
fn main(input: Field) {
    bar(input)
}

Expected Behavior

Expected the tests to pass, as they do with nargo from noirup:

❯ ~/.nargo/bin/nargo --version
nargo version = 1.0.0-beta.2
noirc version = 1.0.0-beta.2+97afa52f5212be2d05af26b9e8dde9c3ea7a1d2e
(git version hash: 97afa52f5212be2d05af26b9e8dde9c3ea7a1d2e, is dirty: false)

❯ ~/.nargo/bin/nargo test

[regression_noir_sort] Running 2 test functions
[regression_noir_sort] Testing test::test_local ... ok
[regression_noir_sort] Testing test::test_global ... ok
[regression_noir_sort] 2 tests passed

Bug

The tests fail with overflow errors:

❯ cargo run test
   Compiling noir_debugger v1.0.0-beta.4 (/home/michael/coding/rust/noir/tooling/debugger)
   Compiling nargo_cli v1.0.0-beta.4 (/home/michael/coding/rust/noir/tooling/nargo_cli)
    Finished `dev` profile [optimized + debuginfo] target(s) in 6.15s
     Running `/home/michael/coding/rust/noir/target/debug/nargo test`
[regression_7372] Running 2 test functions
The application panicked (crashed).
Message:  attempt to subtract with overflow
Location: compiler/noirc_evaluator/src/acir/acir_context/generated_acir/mod.rs:646

This is a bug. We may have already fixed this in newer versions of Nargo so try searching for similar issues at https://github.com/noir-lang/noir/issues/.
If there isn't an open issue for this bug, consider opening one at https://github.com/noir-lang/noir/issues/new?labels=bug&template=bug_report.yml
[regression_7372] Testing test::test_local ... FAIL
attempt to subtract with overflow

The application panicked (crashed).
Message:  attempt to subtract with overflow
Location: compiler/noirc_evaluator/src/acir/acir_context/generated_acir/mod.rs:646

This is a bug. We may have already fixed this in newer versions of Nargo so try searching for similar issues at https://github.com/noir-lang/noir/issues/.
If there isn't an open issue for this bug, consider opening one at https://github.com/noir-lang/noir/issues/new?labels=bug&template=bug_report.yml
[regression_7372] Testing test::test_global ... FAIL
attempt to subtract with overflow


[regression_7372] Failures:
     test::test_local
     test::test_global

[regression_7372] 2 tests failed

Where the panicking line is in GeneratedAcir::last_acir_opcode_location:

OpcodeLocation::Acir(self.opcodes.len() - 1)

To Reproduce

Workaround

None

Workaround Description

No response

Additional Context

No response

Project Impact

None

Blocker Context

No response

Nargo Version

No response

NoirJS Version

No response

Proving Backend Tooling & Version

No response

Would you like to submit a PR for this Issue?

None

Support Needs

No response

[jfecher]

Tested locally: main also fails when you call bar with bar(0) so this is a difference in handling constants & non-constants rather than differences in nargo execute & test.