Bug#580088: jack-audio-connection-kit: FTBFS on armel ("cannot convert 'int' to 'va_list'")

[Simon McVittie]

On Mon, 03 May 2010 at 18:13:00 +0200, Adrian Knoth wrote:
> Obviously, arg4 is NULL, so the message means the compiler cannot
> convert 0 to a va_list, which should be (more or less) a pointer.

Or a struct, or a platform-specific-object that exists nowhere else in C, or a
piece of cheese, depending. (C makes no guarantees about what va_list means; I
doubt C++ does either.)

Googling for "armel va_list" turns up
https://bugs.launchpad.net/ubuntu/+source/gnome-keyring/+bug/527179 which
suggests that va_list is indeed a struct on armel.

> The code in question:
>
>    jack_client_open_aux(client_name, (jack_options_t)options, NULL, NULL);

Instead of trying to fake up an empty va_list, why not call the varargs
version, with only the argument terminator in its varargs?

    jack_client_open(client_name, (jack_options_t)options, NULL, NULL);

I'm assuming here that jack_client_open_aux is to jack_client_open as
vprintf is to printf, i.e. jack_client_open just calls jack_client_open_aux.

Regards,
    S
    (who knows very little about armel or JACK)