我关注公会，克隆项目并运行
make
并收到以下错误：
/home/xx/android-ndk-r9/sources/android/cpufeatures/cpu-features.c:59:35: fatal error: sys/system_properties.h: No such file or directory
compilation terminated.
make[1]: *** [codec/common/cpu-features.o] Error 1
make[1]: Leaving directory `/home/xx/linphone-android/submodules/externals/build/openh264/arm'
make: *** [build-openh264-arm] Error 2
我使用的是Ubuntu 14.4，ndk-r9。有人帮我这个吗？