This works:

    𝕕𝕖𝕗 = 1

This raises SyntaxError:

    import ast
    exec(ast.unparse(ast.parse("𝕕𝕖𝕗 = 1")))

It looks like `ast.parse` creates a `Name` node with `id='def'`, which is correct per PEP 3131, but `ast.unparse` doesn't know it needs to mangle the output somehow, as "𝕕𝕖𝕗" or a similar Unicode replacement.