John E Hein wrote at 08:53 -0700 on Jan  7, 2008:
 > Dustin J. Mitchell wrote at 09:46 -0500 on Jan  7, 2008:
 >  > On Jan 7, 2008 9:03 AM, Mister Olli <mister.olli AT googlemail DOT com> 
 > wrote:
 >  > > (gdb) bt
 >  > > #0  0x281ece17 in shmget () from /lib/libc.so.6
 >  > > #1  0x080520f4 in attach_buffers ()
 >  > > #2  0x0804b872 in main ()
 >  > 
 >  > Eek -- this is where the taper is allocating the memory that it will
 >  > share with the tape-writer process.  Have any FreeBSD folks seen this
 >  > error before?
 > 
 > SIGSYS (non-existent system call) might happen when you have a
 > mismatching userland and kernel.  Your first step is to make sure you
 > have updated your world (via the buildworld/buildkernel processed
 > documented in /usr/src/UPDATING).

Also make sure you have not removed support for System V IPC (shared
memory) in a custom kernel (GENERIC has support for it).