Orbot BUILD instructions incomplete

The instructions for building Orbot are incomplete

https://gitweb.torproject.org/orbot.git/blob/9daaec2f84e59ad49cbff29c11eadbe52cc8f4d4:/BUILD

my NDK_BASE

$NDK_BASEbash: /home/malaparte/src/android/android-ndk-r8c: Is a directory

and

make -C ./externalmake: Entering directory /home/malaparte/src/tor/orbot/external'cd openssl-static && \        ndk-build/bin/sh: 2: ndk-build: not foundmake: *** [openssl-static/obj/local/armeabi/libcrypto.a] Error 127make: Leaving directory /home/malaparte/src/tor/orbot/externa

Trac:
Username: malaparte_