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Description
Describe the Bug
When using Polyglot.eval() from inside Graal-Node.js and an error occurs in either Python or Ruby as the execution language, the user sees a cryptic JS error message instead of the original error.
Steps to Reproduce
Python
$ node --jvm --polyglot
> result = Polyglot.eval('python', 'a + b')
TypeError: Cannot convert undefined or null to object: undefined
at Function.defineProperties (native)
...
Ruby
$ node --jvm --polyglot
> result = Polyglot.eval('ruby', 'a + b')
TypeError: Object prototype may only be an Object or null: DynamicObject@28fe2bef<Method>
at Function.setPrototypeOf (native)
...
Expected Behavior
An error native to the used execution language (Python or Ruby) should be shown signaling that the used variable a is not defined in the scope. See js for an example:
$ node --jvm --polyglot
> result = Polyglot.eval('js', 'a + b')
ReferenceError: a is not defined
at <eval>:1:1
at Object.eval (native)
Actual Behavior
A cryptic error message is shown.
Tested with GraalVM CE 19.0.0 on macOS.
/cc @jak-ing