def _replace_args_with(blocks, args):
    """
    Replace ir.Arg(...) with real arguments from call site
    """
    for label, block in blocks.items():
        assigns = block.find_insts(ir.Assign)
        for stmt in assigns:
            if isinstance(stmt.value, ir.Arg):
                idx = stmt.value.index
                assert (idx < len(args))
                stmt.value = args[idx]

    Replace ir.Arg(...) with real arguments from call site
    
numba/core/inline_closurecall.py