> [maxim@mtbest ~]$ [maxim@mtbest jaybird]$ ./build.sh -f build_native.xml
> Ant binary was found in /usr/bin/ant
> Buildfile: build_native.xml
> [taskdef] Could not load definitions from resource cpptasks.tasks.
> It could not be found.
> [typedef] Could not load definitions from resource cpptasks.types.
> It could not be found.

...

> ANT_HOME environment is set.
> Where is my mistake?

Check whether:

a) ANT_HOME is set to your client-java/ directory
b) if not, copy the client-java/lib/cpptasks.jar to your $ANT_HOME/lib/
directory.

Roman