Hi,
> The implementation of externalCallFailed will
> query for the last error message.
>
> Typically a windows API call returns a result (failed, success
> or error code). If it fails you can use GetLastError()
> to retrieve error information.
Just to point this out as it may cause some confusion otherwise: There
are really "two kinds" of errors we are talking about. One is an error
that happens within the FFI (such as when a type coercion fails) and
this kind of error will reported by #externalCallFailed. If the
function (API) call itself fails #externalCallFailed will not report
an error (as for the FFI the call went out successful). Those errors
(typically indicated by return codes or similar) have to be handled
according to what the documentation for the API says (in this case
calling GetLastError() would be the right thing to do).
> Note that ShellOpen is not the best way to call an external
> executable - it's used for open documents.
> To start an executable the CreateProcess() API is better suited.
Yes, even though I think that in this case shellOpen: was called with
the executable name (and not some document) which should work just
fine, e.g., something like "Win32Shell new shellOpen:'notepad.exe'".
Cheers,
  - Andreas