Cryptic error when accessing missing attribute on js object

[vadimkantorov]

The error should not mention cryptic '�' - should instead print the accessed attribute name. Also the Iodide interface (because of fonts?) this character looks like a little square, not even like a question mark.

On https://alpha.iodide.io:

>>> js.asda
Error: Traceback (most recent call last):
  File "/lib/python3.7/site-packages/pyodide.py", line 44, in eval_code
    return eval(compile(expr, '<eval>', mode='eval'), ns, ns)
  File "<eval>", line 1, in <module>
AttributeError: Unknown attribute '�'

_hiwire_throw_error()@https://alpha.iodide.app/pyodide-0.12.0/pyodide.asm.js:8:38602
{anonymous}()@wasm-function[356]:1239
{anonymous}()@wasm-function[383]:265
Object.Module.__runPython()@https://alpha.iodide.app/pyodide-0.12.0/pyodide.asm.js:8:2027156
Object.Module._runPythonInternal()@https://alpha.iodide.app/pyodide-0.12.0/pyodide.asm.js:8:42817
internal()@https://alpha.iodide.app/pyodide-0.12.0/pyodide.asm.js:8:43382
Object.Module.runPythonAsync()@https://alpha.iodide.app/pyodide-0.12.0/pyodide.asm.js:8:43857