Circuit output is not printed after successful execution

[LukiMueller]

Aim

I want to check the result of my program executions but for some special cases the results are not shown although the witness is generated.
Here are some examples when this is the case.

Examples NOT showing the Circuit output:

pub fn main(in0 : Field) -> pub (Field, Field) {
    let out0 = (in0 * in0);
    let out1 = (in0 * in0);
    (out0, out1)
}

// OR

pub fn main(in0 : Field) -> pub (Field, Field) {
    let out0 = (in0 * in0);
    let out1 = out0;
    (out0, out1)
}

Example showing the Circuit output:

pub fn main(in0 : Field) -> pub (Field, Field) {
    let out0 = (in0 * in0);
    let out1 =  (in0 + in0);
    (out0, out1)
}

// OR

pub fn main(in0 : Field) -> pub (Field, Field) {
    let out0 = (in0 * in0);
    let out1 = 0;
    (out0, out1)
}

In all cases I get Circuit witness successfully solved. Older versions seem to give me the expected Circuit output: for all of the provided test cases.
Was there a change that removed this for some special cases, do I have to provide a flag now, or is this a bug?

Expected Behavior

I expected to receive the circuit output Circuit output: ... after the message Circuit witness successfully solved

Bug

For some programs I do no longer receive a Circuit output: ... although nargo execute prints Circuit witness successfully solved.

To Reproduce

1. Create a new nargo project
2. Create a file main.nr with the content from above and a Prover.toml (with e.g. in0="1")
3. nargo execute

Workaround

None

Workaround Description

No response

Additional Context

No response

Project Impact

None

Blocker Context

No response

Nargo Version

nargo version = 0.38.0 noirc version = 0.38.0+35408ab303f1018c1e2c38e6ea55430a2c89dc4c (git version hash: 35408ab, is dirty: false)

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

[TomAFrench]

Hmm, this is odd. I've confirmed that this exists in master.

I think that this is likely caused by the MergeExpressionOptimizer doing something it shouldn't as the issue pops up when a single witness is returned twice.