Issue using custom unitary operations with incorrect matrices

[annagrin]

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Describe the bug

Trying to register a custom unitary with a matrix that is not sized correctly (ie not 2^n x 2^n) gives an unclear error message (Assertion error)

Steps to reproduce the bug

def register_custom_operation(unitary_index: int, matrix: np.ndarray):
    cudaq.register_operation(f"U_{unitary_index}", matrix)

matrix = np.identity(3)
register_custom_operation(0, matrix)

Expected behavior

Clear error message

Is this a regression? If it is, put the last known working version (or commit) here.

Not a regression

Environment

• CUDA Quantum version:
• Python version:
• C++ compiler:
• Operating system:

Suggestions

No response