In build.xml of derby root there's a vestigial target (+ patch)

In main build.xml, the one at the project's root, there's a target
    engine_169_opt
that executes an
    <ant dir="${derby.engine.src.dir}" target="engine_169_opt"/>
task, against
    java\org.apache.derby.engine\build.xml
that, in turn, DOESNT contain a engine_169_opt target, so it raises an error.
No other build file (in fact, no other FILE in derby) contains an "engine_169_opt" string.
So I think that target engine_169_opt in main build file can be safely removed.
I'll attach (when possible)

1. an svn diff file (the engine_169_opt target removal)
2. and 2 maps (in dot and pdf format) of target relationships of build family files of Derby

Best regards,

    Davide Grandi