https://stackoverflow.com/questions/20762088/build-libaacplus-on-mac-os-10-9#34718904
Actually the "AuChannelOpen" method was implement in frontend/au_channel.h file, but it was a "inline" method. I think that the Makefile disabled the "inline" feature, so simple solutions:
enable "inline".
delete all "inline" words in au_channel.h file.
and if you just need the static library without the program, you can commit the line where call this function in frontend/main.c.
./autogen.sh --with-fftw3 --with-parameter-expansion-string-replace-capable-shell=/bin/bash
Adam Peter Burns