I've already discussed this with a few members of the community, but I would like to raise it with a wider FreeSWITCH audience. Since upgrading to libtool 2.2.6a (now the default in debian testing), I can't successfully link mod_portaudio.so. The system is Debian Testing, x86_64 architecture. ldd -d mod_portaudio.so returns the following (after listing the library dependencies): undefined symbol: snd_config (./mod_portaudio.so) snd_config is from the Alsa library, libasound. mod_portaudio.la shows a reference to /usr/lib/libasound.la, all of which looks correct. I have also examined the build logs, without finding the problem, as there are no errors reported during linking and I didn't find any linker invocations with library parameters apparently missing. The ldd -d output: undefined symbol: snd_config (./mod_portaudio.so) linux-vdso.so.1 => (0x00007fffd31ff000) libm.so.6 => /lib/libm.so.6 (0x00007f0ccacf7000) libfreeswitch.so.1 => /opt/freeswitch/lib/libfreeswitch.so.1 (0x00007f0c ca8c6000) libpthread.so.0 => /lib/libpthread.so.0 (0x00007f0cca6aa000) libc.so.6 => /lib/libc.so.6 (0x00007f0cca357000) libncurses.so.5 => /lib/libncurses.so.5 (0x00007f0cca118000) libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007f0cc9e08000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00007f0cc9bed000) libodbc.so.1 => /usr/lib/libodbc.so.1 (0x00007f0cc998d000) /lib64/ld-linux-x86-64.so.2 (0x00007f0ccb1d1000) libdl.so.2 => /lib/libdl.so.2 (0x00007f0cc9788000) libltdl.so.7 => /usr/lib/libltdl.so.7 (0x00007f0cc957f000) I spent several hours yesterday trying to debug this one. Any suggestions would be welcome. At this stage, I'm not sure whether it's a FreeSWITCH problem or a bug in libtool, or elsewhere.