Problem exist, i used lates sid (all packages synced) and QL crushed with
python-gobject 2.21.4+is.2.21.3-1, but work fine with 2.21.4 version.
2010/11/15 Ian Campbell <i...@hellion.org.uk>
> On Mon, 2010-11-15 at 14:13 -0500, Christine Spang wrote:
> > On Sun, Nov 14, 2010 at 11:23:42AM -0500, Mike Paul wrote:
> > > I was going to take a shot at debugging this today, since it's on the
> RC
> > > bug list for squeeze, but it seems to have resolved itself at some
> > > point, at least in unstable. QL starts without errors, and it's
> playing
> > > music right now.
> > >
> > > The last time I tried it was weeks ago, so unfortunately I don't know
> > > which of the many package updates between then and now was responsible
> > > for the change. I also don't have a system running squeeze, so I can't
> > > test whether it works there. But it's working for me in sid.
> >
> > Thanks for taking a look at this, Mike! Were you able to
> > reproduce this bug before?
> >
> > Ian, can you still reproduce this bug?
>
> I'm afraid so.
>
> I reverted my hacky patch and the issue reoccurred.
>
> The system was pretty out of date so I did an aptitude upgrade, which
> unfortunately didn't help (aptitude upgrade log appended anyway).
>
> I didn't think it was worth logging out and back in again or anything
> like that, but I can try if someone thinks it is worth a go.
>
> > I'm hesitant to close this bug without hearing from Ian, but
> > perhaps downgrading it would be appropriate since I have yet
> > to encounter someone else who is able to reproduce, which
> > suggests that it only appears (appeared?) in very limited
> > circumstances.
>
> I think this bug probably more correctly belongs to the gst python
> bindings (or maybe the gobject bindings framework generally), since I
> can't see how this can be expected to work correctly unless they
> explicitly take action to integrate the gobject/gst reference counting
> of the C objects with python's reference counting when adding objects to
> queues (or whatever, I'm not that familiar with gst terminology). It can
> be worked around in the python user of the bindings by keeping extra
> python references to the objects in question, as my hacky patch does,
> but that doesn't seem right to me.
>
> I suspect the ability to reproduce the issue depends somewhat on the
> pattern of other memory allocations going on etc since that will effect
> how quickly the erroneously freed memory gets reused (if at all), which
> might explain away the small number of people who are seeing this. I
> tried (reasonably hard) to construct a smaller test case which exhibited
> the problem but I was unable to do so.
>
> Does python have a debugging facility which will explicitly poison
> memory on free? Since this issue is in the C bindings perhaps it
> wouldn't help much without explicit bindings support.
>
> Perhaps a similar facility exists in gobject and would be more use here?
> G_DEBUG=gc-friendly looks pretty close, does that help anyone else
> reproduce? (it seem to need a debug version of glib)
>
> Valgrind might also help, a bit of a long shot though.
>
> Ian.
>
> Aptitude 0.6.3: log report
> Mon, Nov 15 2010 19:39:16 +0000
>
> IMPORTANT: this log only lists intended actions; actions which fail due to
> dpkg problems may not be completed.
>
> Will install 81 packages, and remove 9 packages.
> 28.6 MB of disk space will be freed
>
> ===============================================================================
> [REMOVE, NOT USED] libqt4-assistant
> [REMOVE, NOT USED] libqt4-help
> [REMOVE, NOT USED] libqt4-scripttools
> [REMOVE, NOT USED] libqt4-test
> [REMOVE, NOT USED] python-qt4
> [REMOVE, NOT USED] python-qt4-dbus
> [REMOVE, NOT USED] python-reportlab
> [REMOVE, NOT USED] python-reportlab-accel
> [REMOVE, NOT USED] python-sip
> [HOLD] gthumb
> [HOLD] gthumb-data
> [HOLD] lvm2
> [UPGRADE] acpid 1:2.0.6-1 -> 1:2.0.6-2
> [UPGRADE] base-files 5.9 -> 5.10
> [UPGRADE] bcc 0.16.17-3 -> 0.16.17-3.1
> [UPGRADE] bin86 0.16.17-3 -> 0.16.17-3.1
> [UPGRADE] bind9-doc 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] bind9-host 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] bsdmainutils 8.0.15 -> 8.0.16
> [UPGRADE] cdebconf 0.150 -> 0.151
> [UPGRADE] cpp-4.4 4.4.5-6 -> 4.4.5-7
> [UPGRADE] cups 1.4.4-6 -> 1.4.4-7
> [UPGRADE] cups-bsd 1.4.4-6 -> 1.4.4-7
> [UPGRADE] cups-client 1.4.4-6 -> 1.4.4-7
> [UPGRADE] cups-common 1.4.4-6 -> 1.4.4-7
> [UPGRADE] cups-ppdc 1.4.4-6 -> 1.4.4-7
> [UPGRADE] debian-cd 3.1.3 -> 3.1.4
> [UPGRADE] debianutils 3.4.1 -> 3.4.2
> [UPGRADE] debootstrap 1.0.25 -> 1.0.26
> [UPGRADE] dnsutils 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] eatmydata 15-3 -> 15-4
> [UPGRADE] elks-libc 0.16.17-3 -> 0.16.17-3.1
> [UPGRADE] evolution 2.30.3-3 -> 2.30.3-4
> [UPGRADE] evolution-common 2.30.3-3 -> 2.30.3-4
> [UPGRADE] evolution-plugins 2.30.3-3 -> 2.30.3-4
> [UPGRADE] foomatic-filters 4.0.5-5 -> 4.0.5-6
> [UPGRADE] g++-4.4 4.4.5-6 -> 4.4.5-7
> [UPGRADE] gcc-4.4 4.4.5-6 -> 4.4.5-7
> [UPGRADE] gcc-4.4-base 4.4.5-6 -> 4.4.5-7
> [UPGRADE] gdm 2.20.11-2 -> 2.20.11-4
> [UPGRADE] gnome-about 2.30.2-1 -> 2.30.2-2
> [UPGRADE] gnome-desktop-data 2.30.2-1 -> 2.30.2-2
> [UPGRADE] gnome-nettool 2.30.0-2 -> 2.30.0-3
> [UPGRADE] kernel-wedge 2.70 -> 2.71
> [UPGRADE] lib32gcc1 1:4.4.5-6 -> 1:4.4.5-7
> [UPGRADE] lib32stdc++6 4.4.5-6 -> 4.4.5-7
> [UPGRADE] libaudio-dev 1.9.2-3 -> 1.9.2-4
> [UPGRADE] libaudio2 1.9.2-3 -> 1.9.2-4
> [UPGRADE] libbind9-60 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] libbrlapi0.5 4.2-4 -> 4.2-5
> [UPGRADE] libcups2 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcups2-dev 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcupscgi1 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcupsdriver1 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcupsimage2 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcupsmime1 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libcupsppdc1 1.4.4-6 -> 1.4.4-7
> [UPGRADE] libdns69 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] libevolution 2.30.3-3 -> 2.30.3-4
> [UPGRADE] libgfortran3 4.4.5-6 -> 4.4.5-7
> [UPGRADE] libgnome-desktop-2-17 2.30.2-1 -> 2.30.2-2
> [UPGRADE] libgphoto2-2 2.4.6-2 -> 2.4.6-3
> [UPGRADE] libgphoto2-port0 2.4.6-2 -> 2.4.6-3
> [UPGRADE] libgstfarsight0.10-0 0.0.21-2 -> 0.0.22-1
> [UPGRADE] libisc62 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] libisccc60 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] libisccfg62 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] liblwres60 1:9.7.2.dfsg.P2-1 -> 1:9.7.2.dfsg.P2-2
> [UPGRADE] liblzma2 4.999.9beta+20100810-1 -> 5.0.0-2
> [UPGRADE] libmcs1 0.7.1-1 -> 0.7.1-1.1
> [UPGRADE] libstdc++6 4.4.5-6 -> 4.4.5-7
> [UPGRADE] libstdc++6-4.4-dev 4.4.5-6 -> 4.4.5-7
> [UPGRADE] libvdpau1 0.4-5 -> 0.4.1-2
> [UPGRADE] libvpx0 0.9.1-1 -> 0.9.1-2
> [UPGRADE] mime-support 3.48-1 -> 3.51-1
> [UPGRADE] pristine-tar 1.10 -> 1.11
> [UPGRADE] python-brlapi 4.2-4 -> 4.2-5
> [UPGRADE] python-farsight 0.0.21-2 -> 0.0.22-1
> [UPGRADE] python-software-properties 0.60.debian-2 -> 0.60.debian-3
> [UPGRADE] sensible-utils 0.0.4 -> 0.0.5
> [UPGRADE] shared-mime-info 0.71-3 -> 0.71-4
> [UPGRADE] software-properties-gtk 0.60.debian-2 -> 0.60.debian-3
> [UPGRADE] synaptic 0.70~pre1+b1 -> 0.70~pre2
> [UPGRADE] tar 1.24-1.1 -> 1.25-2
> [UPGRADE] vpnc 0.5.3r449-2 -> 0.5.3r449-2.1
> [UPGRADE] x11proto-input-dev 2.0-2 -> 2.0.1-1
> [UPGRADE] xfonts-bitmap-mule 8.5+0.20030825.0433-9 ->
> 8.5+0.20030825.0433-10
> [UPGRADE] xfsprogs 3.1.3 -> 3.1.4
> [UPGRADE] xorg-docs-core 1:1.5-1 -> 1:1.5.99.901-1
> [UPGRADE] xserver-common 2:1.7.7-8 -> 2:1.7.7-9
> [UPGRADE] xserver-xorg-core 2:1.7.7-8 -> 2:1.7.7-9
> [UPGRADE] xserver-xorg-dev 2:1.7.7-8 -> 2:1.7.7-9
> [UPGRADE] xz-utils 4.999.9beta+20100810-1 -> 5.0.0-2
>
> ===============================================================================
>
> Log complete.
>
>
> --
> Ian Campbell
>
> Poverty must have its satisfactions, else there would not be so many poor
> people.
> -- Don Herold
>
System: Linux 2.6.32-5-686 #1 SMP Sat Oct 30 22:47:19 UTC 2010 i686
X Vendor: The X.Org Foundation
X Vendor Release: 10707000
Selinux: No
Accessibility: Disabled
GTK+ Theme: Shiki-Wise
Icon Theme: gnome-brave
GTK+ Modules: gnomebreakpad, canberra-gtk-module
Memory status: size: 149004288 vsize: 149004288 resident: 47837184 share:
22818816 rss: 47837184 rss_rlim: 18446744073709551615
CPU usage: start_time: 1289931675 rtime: 153 utime: 136 stime: 17 cutime:0
cstime: 0 timeout: 0 it_real_value: 0 frequency: 100
Backtrace was generated from '/usr/bin/python2.6'
[Thread debugging using libthread_db enabled]
[New Thread 0xb09a6b70 (LWP 10251)]
[New Thread 0xb187db70 (LWP 10249)]
0xb7789424 in __kernel_vsyscall ()
#0 0xb7789424 in __kernel_vsyscall ()
#1 0xb74eb696 in poll () from /lib/i686/cmov/libc.so.6
#2 0xb707168b in g_poll () from /lib/libglib-2.0.so.0
#3 0xb706418c in ?? () from /lib/libglib-2.0.so.0
#4 0xb70648f7 in g_main_loop_run () from /lib/libglib-2.0.so.0
#5 0xb6aa7ba9 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#6 0xb6eaa6b8 in ?? () from /usr/lib/pymodules/python2.6/gtk-2.0/gtk/_gtk.so
#7 0x080e0c9c in PyEval_EvalFrameEx ()
#8 0x080e18b0 in PyEval_EvalFrameEx ()
#9 0x080e18b0 in PyEval_EvalFrameEx ()
#10 0x080e2507 in PyEval_EvalCodeEx ()
#11 0x080e2607 in PyEval_EvalCode ()
#12 0x080ffcbd in PyRun_FileExFlags ()
#13 0x080fff22 in PyRun_SimpleFileExFlags ()
#14 0x0805dd81 in Py_Main ()
#15 0x0805cf6b in main ()
Thread 3 (Thread 0xb187db70 (LWP 10249)):
#0 0xb7789424 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb7767385 in sem_wait@@GLIBC_2.1 () from /lib/i686/cmov/libpthread.so.0
No symbol table info available.
#2 0x0810a518 in PyThread_acquire_lock ()
No symbol table info available.
#3 0x0810e84c in ?? ()
No symbol table info available.
#4 0x080e0721 in PyEval_EvalFrameEx ()
No symbol table info available.
#5 0x080e2507 in PyEval_EvalCodeEx ()
No symbol table info available.
#6 0x080e098b in PyEval_EvalFrameEx ()
No symbol table info available.
#7 0x080e2507 in PyEval_EvalCodeEx ()
No symbol table info available.
#8 0x080e098b in PyEval_EvalFrameEx ()
No symbol table info available.
#9 0x080e2507 in PyEval_EvalCodeEx ()
No symbol table info available.
#10 0x0816b8ef in ?? ()
No symbol table info available.
#11 0x0806232a in PyObject_Call ()
No symbol table info available.
#12 0x080df7b1 in PyEval_EvalFrameEx ()
No symbol table info available.
#13 0x080e18b0 in PyEval_EvalFrameEx ()
No symbol table info available.
#14 0x080e18b0 in PyEval_EvalFrameEx ()
No symbol table info available.
#15 0x080e2507 in PyEval_EvalCodeEx ()
No symbol table info available.
#16 0x0816b80c in ?? ()
No symbol table info available.
#17 0x0806232a in PyObject_Call ()
No symbol table info available.
#18 0x0806a311 in ?? ()
No symbol table info available.
#19 0x0806232a in PyObject_Call ()
No symbol table info available.
#20 0x080db582 in PyEval_CallObjectWithKeywords ()
No symbol table info available.
#21 0x0810ecdf in ?? ()
No symbol table info available.
#22 0xb7760955 in start_thread () from /lib/i686/cmov/libpthread.so.0
No symbol table info available.
#23 0xb74f8e7e in clone () from /lib/i686/cmov/libc.so.6
No symbol table info available.
Thread 2 (Thread 0xb09a6b70 (LWP 10251)):
#0 0xb7789424 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb7768f4b in waitpid () from /lib/i686/cmov/libpthread.so.0
No symbol table info available.
#2 0xb70a9d47 in g_spawn_sync () from /lib/libglib-2.0.so.0
No symbol table info available.
#3 0xb70aa04c in g_spawn_command_line_sync () from /lib/libglib-2.0.so.0
No symbol table info available.
#4 0xb61fa8f4 in ?? () from /usr/lib/gtk-2.0/modules/libgnomebreakpad.so
No symbol table info available.
#5 <signal handler called>
No symbol table info available.
#6 0xb746d59b in vfprintf () from /lib/i686/cmov/libc.so.6
No symbol table info available.
#7 0xb748cdd7 in vasprintf () from /lib/i686/cmov/libc.so.6
No symbol table info available.
#8 0xb70a7717 in g_vasprintf () from /lib/libglib-2.0.so.0
No symbol table info available.
#9 0xb7083c72 in g_strdup_vprintf () from /lib/libglib-2.0.so.0
No symbol table info available.
#10 0xb5d1530c in _gst_element_error_printf () from
/usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#11 0xb00a81b3 in ?? () from /usr/lib/gstreamer-0.10/libgstplaybin.so
No symbol table info available.
#12 0xb00aa6c1 in ?? () from /usr/lib/gstreamer-0.10/libgstplaybin.so
No symbol table info available.
#13 0xb009e522 in ?? () from /usr/lib/gstreamer-0.10/libgstplaybin.so
No symbol table info available.
#14 0xb710edec in g_cclosure_marshal_VOID__VOID () from
/usr/lib/libgobject-2.0.so.0
No symbol table info available.
#15 0xb70fec02 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#16 0xb71182ad in ?? () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#17 0xb711991c in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#18 0xb711a032 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#19 0xb5d18ffa in gst_element_no_more_pads () from
/usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#20 0xb0087b18 in ?? () from /usr/lib/gstreamer-0.10/libgstdecodebin2.so
No symbol table info available.
#21 0xb710edec in g_cclosure_marshal_VOID__VOID () from
/usr/lib/libgobject-2.0.so.0
No symbol table info available.
#22 0xb70fec02 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#23 0xb71182ad in ?? () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#24 0xb711991c in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#25 0xb711a032 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#26 0xb5d18ffa in gst_element_no_more_pads () from
/usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#27 0xb007ea4f in ?? () from /usr/lib/gstreamer-0.10/libgstdecodebin2.so
No symbol table info available.
#28 0xb007fc8f in ?? () from /usr/lib/gstreamer-0.10/libgstdecodebin2.so
No symbol table info available.
#29 0xb5d2e2e1 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#30 0xb5d30bf7 in gst_pad_push_event () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#31 0xb001ab11 in ?? () from /usr/lib/gstreamer-0.10/libgstflump3dec.so
No symbol table info available.
#32 0xb5d304c2 in gst_pad_send_event () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#33 0xb5d30a8a in gst_pad_push_event () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#34 0xb5d66222 in gst_element_found_tags_for_pad () from
/usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#35 0xb0049799 in ?? () from /usr/lib/gstreamer-0.10/libgstmpegaudioparse.so
No symbol table info available.
#36 0xb004cd8d in ?? () from /usr/lib/gstreamer-0.10/libgstmpegaudioparse.so
No symbol table info available.
#37 0xb5d32a9d in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#38 0xb5d334c7 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#39 0xb6fc3a52 in ?? () from /usr/lib/libgsttag-0.10.so.0
No symbol table info available.
#40 0xb5d32a9d in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#41 0xb5d334c7 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#42 0xb5c391a3 in ?? () from /usr/lib/gstreamer-0.10/libgstcoreelements.so
No symbol table info available.
#43 0xb5d32a9d in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#44 0xb5d334c7 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#45 0xb5d21a3d in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#46 0xb5d32a9d in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#47 0xb5d334c7 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#48 0xb5dcc40a in ?? () from /usr/lib/libgstbase-0.10.so.0
No symbol table info available.
#49 0xb5d612c1 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#50 0xb5d62887 in ?? () from /usr/lib/libgstreamer-0.10.so.0
No symbol table info available.
#51 0xb708d214 in ?? () from /lib/libglib-2.0.so.0
No symbol table info available.
#52 0xb708b2cf in ?? () from /lib/libglib-2.0.so.0
No symbol table info available.
#53 0xb7760955 in start_thread () from /lib/i686/cmov/libpthread.so.0
No symbol table info available.
#54 0xb74f8e7e in clone () from /lib/i686/cmov/libc.so.6
No symbol table info available.
Thread 1 (Thread 0xb742c6c0 (LWP 10248)):
#0 0xb7789424 in __kernel_vsyscall ()
No symbol table info available.
#1 0xb74eb696 in poll () from /lib/i686/cmov/libc.so.6
No symbol table info available.
#2 0xb707168b in g_poll () from /lib/libglib-2.0.so.0
No symbol table info available.
#3 0xb706418c in ?? () from /lib/libglib-2.0.so.0
No symbol table info available.
#4 0xb70648f7 in g_main_loop_run () from /lib/libglib-2.0.so.0
No symbol table info available.
#5 0xb6aa7ba9 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#6 0xb6eaa6b8 in ?? () from /usr/lib/pymodules/python2.6/gtk-2.0/gtk/_gtk.so
No symbol table info available.
#7 0x080e0c9c in PyEval_EvalFrameEx ()
No symbol table info available.
#8 0x080e18b0 in PyEval_EvalFrameEx ()
No symbol table info available.
#9 0x080e18b0 in PyEval_EvalFrameEx ()
No symbol table info available.
#10 0x080e2507 in PyEval_EvalCodeEx ()
No symbol table info available.
#11 0x080e2607 in PyEval_EvalCode ()
No symbol table info available.
#12 0x080ffcbd in PyRun_FileExFlags ()
No symbol table info available.
#13 0x080fff22 in PyRun_SimpleFileExFlags ()
No symbol table info available.
#14 0x0805dd81 in Py_Main ()
No symbol table info available.
#15 0x0805cf6b in main ()
No symbol table info available.
A debugging session is active.
Inferior 1 [process 10248] will be detached.
Quit anyway? (y or n) [answered Y; input not from terminal]
----------- .xsession-errors ---------------------
/usr/lib/pymodules/python2.6/quodlibet/debug/debugwindow.py:111: Warning:
g_object_set_qdata_full: assertion `G_IS_OBJECT (object)' failed
self.__fill_list(view, model, value, traceback)
Quod Libet уже запущен.
Инициализация модуля аудиовывода (gstbe)
Инициализация фонотеки (~/.quodlibet/songs)
Поддерживаемые форматы: mp3, mp4, mpc, spc, trueaudio, wav, wavpack, wma, xiph
Traceback (most recent call last):
File "/usr/lib/pymodules/python2.6/quodlibet/player/gstbe.py", line 182, in
do_set_property
self._vol_element.set_property('volume', v)
TypeError: object at 0xacee43c of type __main__.GstVolume is not initialized
sys:1: Warning: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(quodlibet:10248): GStreamer-CRITICAL **: gst_element_set_state: assertion
`GST_IS_ELEMENT (element)' failed
(quodlibet:10248): GStreamer-CRITICAL **: gst_element_set_state: assertion
`GST_IS_ELEMENT (element)' failed
--------------------------------------------------
