Sets an error within the asynchronous result without a GError. Unless writing a binding, see g_simple_async_result_set_error().
a GQuark (usually G_IO_ERROR).
an error code.
a formatted error reporting string.
va_list of arguments.
See Implementation
Sets an error within the asynchronous result without a GError. Unless writing a binding, see g_simple_async_result_set_error().