Re: Gio::DBus::Connection error: GLib-GIO:ERROR:/build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:4096:invoke_get_property_in_idle_cb: assertion failed: (error != NULL)

[Kjell Ahlstedt <kjell ahlstedt bredband net>]

It would probably be helpful if you can get backtraces also from the 
first two messages. If your three messages have a common cause, the 
first message might be the most interesting one. You can get backtraces 
from "GLib-CRITICAL **: g_variant_ref_sink: assertion `value != NULL' 
failed" if you set a breakpoint in gdb on the function g_log.

Kjell

2012-12-23 07:36, Phong Cao skrev:
> Hi everybody,
>
> I am trying to implement the MPRISv2 interface for my app to integrate 
> it to the Ubuntu's soundmenu. The code compiled successfully. However, 
> the application raised a core dumped when running:
>
> (Dingo Media Manager:6521): GLib-CRITICAL **: g_variant_ref_sink: 
> assertion `value != NULL' failed
>
> (Dingo Media Manager:6521): GLib-CRITICAL **: g_variant_ref_sink: 
> assertion `value != NULL' failed
> **
> GLib-GIO:ERROR:/build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:4096:invoke_get_property_in_idle_cb: 
> assertion failed: (error != NULL)
> Aborted (core dumped)
>
> I guess this problem may be from somewhere within my application. 
> However, I really can't spot the error just looking at the above error 
> message because I don't really know what they mean... Here is the 
> backtrace in GDB:
>
> Program received signal SIGABRT, Aborted.
> 0x00007ffff4237425 in __GI_raise (sig=<optimized out>)
>     at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
> 64    ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
> (gdb) backtrace
> #0  0x00007ffff4237425 in __GI_raise (sig=<optimized out>)
>     at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
> #1  0x00007ffff423ab8b in __GI_abort () at abort.c:91
> #2  0x00007ffff5629b87 in g_assertion_message (
>     domain=domain@entry=0x7ffff284dde1 "GLib-GIO",
>     file=file@entry=0x7ffff286f7c8 
> "/build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c", 
> line=line@entry=4096,
>     func=func@entry=0x7ffff2871550 <__PRETTY_FUNCTION__.23801> 
> "invoke_get_property_in_idle_cb", message=<optimized out>)
>     at /build/buildd/glib2.0-2.34.1/./glib/gtestutils.c:1877
> #3  0x00007ffff562a0a4 in g_assertion_message_expr (
>     domain=domain@entry=0x7ffff284dde1 "GLib-GIO",
>     file=file@entry=0x7ffff286f7c8 
> "/build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c", 
> line=line@entry=4096,
>     func=func@entry=0x7ffff2871550 <__PRETTY_FUNCTION__.23801> 
> "invoke_get_property_in_idle_cb", expr=expr@entry=0x7ffff286c8e6 
> "error != NULL")
>     at /build/buildd/glib2.0-2.34.1/./glib/gtestutils.c:1888
> #4  0x00007ffff281ca01 in invoke_get_property_in_idle_cb 
> (_data=0x7fffe40030b0)
>     at /build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:4096
> #5  invoke_get_property_in_idle_cb (_data=0x7fffe40030b0)
>     at /build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:4052
> #6  0x00007ffff5607ab5 in g_main_dispatch (context=0x7a7800)
>     at /build/buildd/glib2.0-2.34.1/./glib/gmain.c:2715
>
> Can anybody here having experience in Gio::DBus and GDBusConnection 
> explain these for me? I am a newbie in DBus and desperately need help.
>
> Thank you for reading my message and answering my question! Have a 
> good weekend!
>
>
> Best regards,
>
>
> Phong Cao