Result incorrect when using ~ to invert a single bit variable

[bread34657]

Description

When using ~ to invert a single bit of 0, the result should be 1.
When using ~ to invert a single bit of 1, the result should be 0.

Scenario Code

action example {
    activity {
        do invertSingleBit with { val in [0]; };
        do invertSingleBit with { val in [1]; };
    }
}
action invertSingleBit {
    rand bit val;
    bit val_n;
    exec post_solve {
        val_n = ~val;
    }
    exec body ASM = """invertSingleBit: {{val}} -> {{val_n}}""";
}

Expected Output or Behaviour

invertSingleBit: 0 -> 1
invertSingleBit: 1 -> 0

Error Message from PSSGen or JAVA

1,2c1,2
< invertSingleBit: 0 -> -1
< invertSingleBit: 1 -> -2
---
> invertSingleBit: 0 -> 1
> invertSingleBit: 1 -> 0
Test Result: FAIL

Additional Context (Optional)

Please feel free to add any other context about the problem here.