Created attachment 209
1.patch

If segfaults when build with gstreamer support:
Starting program: /usr/bin/workrave 
[Thread debugging using libthread_db enabled]
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib64/libgobject-2.0.so.0.2200.5-gdb.py", line 9, in <module>
    from gobject import register
  File "/usr/share/glib-2.0/gdb/gobject.py", line 3, in <module>
    import gdb.backtrace
ImportError: No module named backtrace
[New Thread 0x7fffeeaa0710 (LWP 24225)]

Program received signal SIGSEGV, Segmentation fault.
0x0000000000493571 in SoundPlayer::init (this=0x77cbb0) at SoundPlayer.cc:337
337	SoundPlayer.cc: No such file or directory.
	in SoundPlayer.cc
#0  0x0000000000493571 in SoundPlayer::init (this=0x77cbb0) at SoundPlayer.cc:337
#1  0x0000000000454501 in GUI::init_sound_player (this=0x6e13f0) at GUI.cc:867
#2  0x0000000000456299 in GUI::main (this=0x6e13f0) at GUI.cc:212
#3  0x00000000004706b0 in run (argc=1, argv=0x7fffffffddd8) at main.cc:59
#4  0x00007ffff1c7bbbd in __libc_start_main () from /lib/libc.so.6
#5  0x000000000044fec9 in _start ()
#0  0x0000000000493571 in SoundPlayer::init (this=0x77cbb0) at SoundPlayer.cc:337
#1  0x0000000000454501 in GUI::init_sound_player (this=0x6e13f0) at GUI.cc:867
#2  0x0000000000456299 in GUI::main (this=0x6e13f0) at GUI.cc:212
#3  0x00000000004706b0 in run (argc=1, argv=0x7fffffffddd8) at main.cc:59
#4  0x00007ffff1c7bbbd in __libc_start_main () from /lib/libc.so.6
#5  0x000000000044fec9 in _start ()
The program being debugged has been started already.
Start it from the beginning? (y or n) Program not restarted.
Continuing.
[Thread 0x7fffeeaa0710 (LWP 24225) exited]

Program terminated with signal SIGSEGV, Segmentation fault.
The program no longer exists.

Downstream, people have provided a patch that seems to solve this issue:
http://bugs.gentoo.org/attachment.cgi?id=188060&action=view

Thanks for taking care of this one

Thanks. This bug will be fixed in 1.9.2

How did you finally fixed it? That patch seemed to finally not work :-(
http://bugs.gentoo.org/show_bug.cgi?id=310261#c6

You also need an additional "if (driver != NULL)" in the init function:

void
SoundPlayer::init()
{
  driver->init();
  register_sound_events();
}

SoundPlayer crashes when no sound driver (on linux, the deprecated gnome sounds events, or gstreamer) is found. Even if you fix this crash, Workrave will have no sound support.