export SYSROOT="$ANDROID_NDK_ROOT/platforms/android-21/arch-arm64"
export CFLAGS="--sysroot=$SYSROOT"
export LDFLAGS="--sysroot=$SYSROOT"
export PATH=/opt/android-ndk/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin:$PATH
./configure --host=aarch64-linux-android --disable-syslog