Divide by zero in 9_conditional

[jfecher]

Aim

Tried to prove and verify test 9_conditional with the --experimental-ssa flag

Expected Behavior

Expected the test to prove and verify

Bug

The program panics with:

The application panicked (crashed).
Message:  attempt to divide by zero
Location: ~/.cargo/registry/src/github.com-1ecc6299db9ec823/num-bigint-0.4.3/src/biguint/division.rs:70

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

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                                ⋮ 12 frames hidden ⋮                              
  13: num_bigint::biguint::division::rem_digit::hab9de1142251a43f
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/num-bigint-0.4.3/src/biguint/division.rs:70
  14: num_bigint::biguint::division::<impl core::ops::arith::Rem<u32> for &num_bigint::biguint::BigUint>::rem::h9f36fdba14c97c2f
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/num-bigint-0.4.3/src/biguint/division.rs:509
  15: num_bigint::biguint::division::<impl core::ops::arith::Rem<&num_bigint::biguint::BigUint> for &num_bigint::biguint::BigUint>::rem::h0f3ff2a5055a0e24
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/num-bigint-0.4.3/src/biguint/division.rs:484
  16: acvm::pwg::directives::solve_directives_internal::hd535679e0369505c
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/acvm-0.15.1/src/pwg/directives/mod.rs:61
  17: acvm::pwg::directives::solve_directives::hfbb5440f88e5e677
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/acvm-0.15.1/src/pwg/directives/mod.rs:27
  18: acvm::pwg::solve::h04119895763b2f4d
      at ~/.cargo/registry/src/github.com-1ecc6299db9ec823/acvm-0.15.1/src/pwg/mod.rs:120
  19: nargo::ops::execute::execute_circuit::hf1d169eb4c52d7a1
      at noir/crates/nargo/src/ops/execute.rs:14
  20: nargo_cli::cli::execute_cmd::execute_program::hfab95fe37eeca478
      at noir/crates/nargo_cli/src/cli/execute_cmd.rs:82
  21: nargo_cli::cli::prove_cmd::prove_with_path::h552b36acab6b610f
      at noir/crates/nargo_cli/src/cli/prove_cmd.rs:125
  22: nargo_cli::cli::prove_cmd::run::h01a47cfb101544d5
      at noir/crates/nargo_cli/src/cli/prove_cmd.rs:65
  23: nargo_cli::cli::start_cli::hdf9ebb41a12edf18
      at noir/crates/nargo_cli/src/cli/mod.rs:77
  24: nargo::main::h4caa4dc2a2c3a0a7
      at noir/crates/nargo_cli/src/main.rs:14
  25: core::ops::function::FnOnce::call_once::hd5f7091a178804ee
      at /rustc/69f9c33d71c871fc16ac445211281c6e7a340943/library/core/src/ops/function.rs:251
                                ⋮ 13 frames hidden ⋮                              
exit 101

To Reproduce

Installation Method

None

Nargo Version

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

No response

[jfecher]

Looks like this is caused by the parameter a of main being set to 0 in the Prover.toml. We produce a div instruction using it:

fn main f0 {
  b0(v0: Field, ..):
    ..
    v33601 = div v33442, v0
    ..

The error is while running execute_cmd so I'm not sure why it is only occurring now.

[kevaundray]

a minified example of this problem would be:

use dep::std;

fn main(a: u32, b: u32) ->pub u32{
    b / a % a
}

[kevaundray]

Seems the error is in the quotient directive:

.cargo/registry/src/github.com-1ecc6299db9ec823/acvm-0.18.1/src/pwg/directives/mod.rs:64

This line in particular:

 (&int_a % &int_b, &int_a / &int_b)

Where int_b is zero