[pypy-dev] "Don't know how to convert" error

[Armin Rigo]

Hi Timothy,

On Sat, Aug 25, 2012 at 5:53 AM, Timothy Baldridge <tbaldridge at gmail.com> wrote:
> [translation:ERROR]  TyperError: don't know how to convert from
> <InstanceRepr for system.core.Object> to <VoidRepr Void>
> [translation:ERROR] .. (system.rt:60)PolymorphicFunc.invoke3
> [translation:ERROR] .. block at 48 with 1 exits
> [translation:ERROR] .. v14 = simple_call(v13, a_0, b_0, c_0)
>
> What could cause something like this? I can seem to figure out how to even
> go debugging this. I dug into the stack trace a bit and poked around in the
> locals, but I can't seem to find any more information.

The problem is located in the system.rt module line 60, in
PolymorphicFunc.invoke3().  It's probably a method call with three
arguments called a, b, c.  The error means there is some inconsistency
between the type annotation (found "Void", maybe for the result of the
call) and the actual RTyped call (which returns an instance of
"system.core.Object").  It may be a bug of the ootype type system.
That's all I can guess without inspecting the complete RPython sources
(and not just the invoke3() function).


A bientôt,

Armin.