Globalcall issues with 1.2.15

Running bayonne --trace --driver globalcall gives
...
dso: globalcall.ivr: /usr/local/lib/bayonne/1.2.15/globalcall.ivr: undefined symbol: _ZN3ost14DialogicDriver10EventErrorEP9META
/usr/local/lib/bayonne/1.2.15/globalcall.ivr: undefined symbol: _ZN3ost14DialogicDriver10EventErrorEP9METAEVENT
trace: pid=16384 reason=-1
trace(0): /usr/local/lib/bayonne/1.2.15/bayonne.bin(_ZN3ost5Debug10stackTraceEi+0x23) [0x807ea93]
trace(1): /usr/local/lib/bayonne/1.2.15/trace.dbg(_ZN3ost10TraceDebug10debugFinalEi+0x11) [0x40169a41]
trace(2): /usr/local/lib/bayonne/1.2.15/bayonne.bin [0x805c440]
trace(3): /usr/local/lib/bayonne/1.2.15/bayonne.bin [0x805f918]
trace(4): /usr/local/lib/bayonne/1.2.15/bayonne.bin(main+0x289) [0x80601e9]
trace(5): /lib/libc.so.6(__libc_start_main+0xc6) [0x403e2e36]
trace(6): /usr/local/lib/bayonne/1.2.15/bayonne.bin(_ZN3ost8MemPager5firstEj+0x39) [0x805ac31]

After passing through c++filt, that becomes:

dso: globalcall.ivr: /usr/local/lib/bayonne/1.2.15/globalcall.ivr: undefined symbol: _ZN3ost14DialogicDriver10EventErrorEP9META
/usr/local/lib/bayonne/1.2.15/globalcall.ivr: undefined symbol: ost::DialogicDriver::EventError(METAEVENT*)
trace: pid=16384 reason=-1
trace(0): /usr/local/lib/bayonne/1.2.15/bayonne.bin(ost::Debug::stackTrace(int)+0x23) [0x807ea93]
trace(1): /usr/local/lib/bayonne/1.2.15/trace.dbg(ost::TraceDebug::debugFinal(int)+0x11) [0x40169a41]
trace(2): /usr/local/lib/bayonne/1.2.15/bayonne.bin [0x805c440]
trace(3): /usr/local/lib/bayonne/1.2.15/bayonne.bin [0x805f918]
trace(4): /usr/local/lib/bayonne/1.2.15/bayonne.bin(main+0x289) [0x80601e9]
trace(5): /lib/libc.so.6(__libc_start_main+0xc6) [0x403e2e36]
trace(6): /usr/local/lib/bayonne/1.2.15/bayonne.bin(ost::MemPager::first(unsigned int)+0x39) [0x805ac31]

Is this a known problem? This is Dialogic SR6.1 [demo version, actually] on debian sarge