Running this command in a shell produces a segfault:

oggenc -b 80 --advanced-encode-option disable_coupling -o out.ogg in.wav

With a libvorbisenc compiled with debug symbols, here is what gdb tells:

(gdb) run
Starting program: /usr/bin/oggenc -b 80 --advanced-encode-option disable_coupling -o out.ogg in.wav
Ouverture avec le module wav: WAV file reader
Encodage de "in.wav"
         en "out.ogg"
au dbit approximatif de 80 kbps (encodage VBR en cours)
Setting advanced encoder option "disable_coupling"

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff791dfb0 in vorbis_encode_setup_setting (vi=0x7fffffffd640, channels=2, rate=44100) at vorbisenc.c:884
(gdb) bt
#0  0x00007ffff791dfb0 in vorbis_encode_setup_setting (vi=0x7fffffffd640, channels=2, rate=44100) at vorbisenc.c:884
#1  0x00007ffff791ed14 in vorbis_encode_ctl (vi=0x7fffffffd640, number=65, arg=0x7fffffffd84c) at vorbisenc.c:1208
#2  0x0000000000407725 in set_advanced_encoder_options (vi=0x7fffffffd640, count=1, opts=<optimized out>) at encode.c:102
#3  oe_encode (opt=0x7fffffffdf70) at encode.c:348
#4  0x0000000000403666 in main (argc=<optimized out>, argv=<optimized out>) at oggenc.c:431
(gdb)

I can reproduce this with any wav input file.

I'm on Ubuntu 12.04 x64, with libvorbisenc 2.0.8.