I can report that this problem (the failure of mod_portaudio.so to be linked properly) still persists as of revision 13970. The operating system is Debian Testing, and the difficulty began after upgrading from Libtool 1 to Libtool 2.2.6a. If anyone else can reproduce this or suggest a means of tracking down the cause, this would be much appreciated. The result of running ldd -r on mod_portaudio.so is as follows. It shows that most of the undefined symbols are from the Alsa library. I have also searched my build logs, (even with VERBOSE=1) but without locating any output that seems suspect. linux-vdso.so.1 => (0x00007fff279ff000) libm.so.6 => /lib/libm.so.6 (0x00007f261f415000) libfreeswitch.so.1 => /opt/freeswitch/lib/libfreeswitch.so.1 (0x00007f261efd5000) libpthread.so.0 => /lib/libpthread.so.0 (0x00007f261edb9000) libc.so.6 => /lib/libc.so.6 (0x00007f261ea66000) libssl.so.0.9.8 => /usr/lib/libssl.so.0.9.8 (0x00007f261e814000) libcrypto.so.0.9.8 => /usr/lib/libcrypto.so.0.9.8 (0x00007f261e473000) libncurses.so.5 => /lib/libncurses.so.5 (0x00007f261e234000) libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007f261df25000) libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00007f261dd09000) libodbc.so.1 => /usr/lib/libodbc.so.1 (0x00007f261daa9000) /lib64/ld-linux-x86-64.so.2 (0x00007f261f8ee000) libdl.so.2 => /lib/libdl.so.2 (0x00007f261d8a5000) libz.so.1 => /usr/lib/libz.so.1 (0x00007f261d68d000) libltdl.so.7 => /usr/lib/libltdl.so.7 (0x00007f261d484000) undefined symbol: crypt_r (/opt/freeswitch/lib/libfreeswitch.so.1) undefined symbol: clock_gettime (/opt/freeswitch/lib/libfreeswitch.so.1) undefined symbol: snd_config (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_period_size_min (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_channels (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_period_size_near (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_rate_near (./mod_portaudio.so) undefined symbol: clock_gettime (./mod_portaudio.so) undefined symbol: snd_pcm_poll_descriptors_revents (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_access (./mod_portaudio.so) undefined symbol: snd_pcm_format_size (./mod_portaudio.so) undefined symbol: snd_strerror (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_periods_min (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_rate (./mod_portaudio.so) undefined symbol: snd_pcm_info_set_device (./mod_portaudio.so) undefined symbol: snd_pcm_status (./mod_portaudio.so) undefined symbol: snd_pcm_close (./mod_portaudio.so) undefined symbol: snd_lib_error_set_handler (./mod_portaudio.so) undefined symbol: snd_config_get_id (./mod_portaudio.so) undefined symbol: snd_pcm_avail_update (./mod_portaudio.so) undefined symbol: snd_pcm_info_set_subdevice (./mod_portaudio.so) undefined symbol: snd_pcm_area_copy (./mod_portaudio.so) undefined symbol: snd_pcm_state (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_channels_min (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_period_size (./mod_portaudio.so) undefined symbol: snd_pcm_info_get_card (./mod_portaudio.so) undefined symbol: snd_pcm_poll_descriptors_count (./mod_portaudio.so) undefined symbol: snd_ctl_open (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_buffer_size_min (./mod_portaudio.so) undefined symbol: snd_config_update (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_channels_max (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_test_format (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_buffer_size_max (./mod_portaudio.so) undefined symbol: snd_ctl_card_info_get_name (./mod_portaudio.so) undefined symbol: snd_pcm_status_sizeof (./mod_portaudio.so) undefined symbol: snd_pcm_delay (./mod_portaudio.so) undefined symbol: snd_pcm_drain (./mod_portaudio.so) undefined symbol: snd_pcm_status_get_tstamp (./mod_portaudio.so) undefined symbol: snd_pcm_start (./mod_portaudio.so) undefined symbol: snd_pcm_open (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_periods_integer (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_test_access (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_silence_threshold (./mod_portaudio.so) undefined symbol: snd_pcm_areas_silence (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_format (./mod_portaudio.so) undefined symbol: snd_ctl_close (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_xfer_align (./mod_portaudio.so) undefined symbol: snd_pcm_mmap_commit (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_sizeof (./mod_portaudio.so) undefined symbol: snd_config_update_free_global (./mod_portaudio.so) undefined symbol: snd_pcm_mmap_begin (./mod_portaudio.so) undefined symbol: snd_ctl_card_info (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_get_boundary (./mod_portaudio.so) undefined symbol: snd_ctl_pcm_next_device (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_periods_max (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params (./mod_portaudio.so) undefined symbol: snd_config_get_string (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_any (./mod_portaudio.so) undefined symbol: snd_pcm_status_get_state (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_test_period_size (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_current (./mod_portaudio.so) undefined symbol: snd_pcm_link (./mod_portaudio.so) undefined symbol: snd_config_iterator_entry (./mod_portaudio.so) undefined symbol: snd_pcm_poll_descriptors (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_set_buffer_size_near (./mod_portaudio.so) undefined symbol: snd_pcm_info_sizeof (./mod_portaudio.so) undefined symbol: snd_ctl_pcm_info (./mod_portaudio.so) undefined symbol: snd_pcm_nonblock (./mod_portaudio.so) undefined symbol: snd_config_search (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_rate_numden (./mod_portaudio.so) undefined symbol: snd_ctl_card_info_sizeof (./mod_portaudio.so) undefined symbol: snd_pcm_drop (./mod_portaudio.so) undefined symbol: snd_config_iterator_end (./mod_portaudio.so) undefined symbol: snd_config_iterator_next (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_start_threshold (./mod_portaudio.so) undefined symbol: snd_pcm_status_get_trigger_tstamp (./mod_portaudio.so) undefined symbol: snd_pcm_info_set_stream (./mod_portaudio.so) undefined symbol: snd_pcm_info (./mod_portaudio.so) undefined symbol: snd_config_iterator_first (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_stop_threshold (./mod_portaudio.so) undefined symbol: snd_card_next (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_silence_size (./mod_portaudio.so) undefined symbol: snd_pcm_status_get_delay (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_buffer_size (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_avail_min (./mod_portaudio.so) undefined symbol: snd_pcm_info_get_name (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params (./mod_portaudio.so) undefined symbol: snd_pcm_prepare (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_sizeof (./mod_portaudio.so) undefined symbol: snd_pcm_hw_params_get_period_size_max (./mod_portaudio.so) undefined symbol: snd_pcm_sw_params_set_tstamp_mode (./mod_portaudio.so)