Unable to compile Native extension

Rhomobile version 5.5 followed the example for creating native extension from docs.tau-technologies.com/en/5.5/guide/native_extensions

When i run build:android:production it fails with
Build extension (arm): greeting
-----------------------------------------------
PWD: (project_path)/extensions/greeting/ext/platform/android
rake arch:arm --trace
cd (project_path)/extensions/greeting/ext/platform/android
cd ../../..
** Invoke arch:arm (first_time)
** Invoke (project_path)/bin/target/android/debug/extensions/greeting/armeabi/libgreeting.a (first_time)
rake aborted!
Don't know how to build task '(project_path)/bin/tmp/greeting/arm/Greeting.cpp.o'
(rhostudio_path)/rake-10.1.1/lib/rake/task_manager.rb:49:in '[]'
(rhostudio_path)/rake-10.1.1/lib/rake/task.rb:53:in 'lookup_prerequisite'
(rhostudio_path)/rake-10.1.1/lib/rake/task.rb:49:in 'block in prerequisite_tasks'


Any help to get this to work would be much appreciated

Thanks Before