我试图在MasOS和Linux Ubuntu上构建linphone-android，但两次都遇到了同样的错误。此错误有多个线程，但还没有解决方案。希望你们中的一些人可以给我一个建议。这是错误：
...
/home/romans/Development/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi-v7a/libopencoreamr.a(wrapper.o): in function Encoder_Interface_Encode:jni/..//submodules/externals/build/opencore-amr/../../opencore-amr/amrnb/wrapper.cpp:66: error: undefined reference to 'my_AMREncode'
collect2: ld returned 1 exit status
make[1]: *** [obj/local/armeabi-v7a/liblinphone-armeabi-v7a.so] Error 1
make[1]: Leaving directory `/home/romans/Development/linphone/linphone-android'
make: *** [generate-libs] Error 2