Ant is assuming Sun's JRE

Binary package hint: ant

While bulding wrapper-3.2.3 (Not a Ubuntu/Debian package yet) - http://wrapper.tanukisoftware.org/doc/english/introduction.html :

BUILD FAILED
/home/bluecommand/Workbench/freenet/real/deb/wrapper-3.2.3/build.xml:429: Can't load javah

        <javah
            destdir="${src.dir}/c"
            classpath="${build.classes}">
            <class name="org.tanukisoftware.wrapper.WrapperManager"/>
        </javah>

In ./src/main/org/apache/tools/ant/taskdefs/optional/javah/SunJavah.java , line 57:
c = Class.forName("com.sun.tools.javah.Main");
...
throw new BuildException(
                "Can't load javah", ex, javah.getLocation());

This needs to be gnu.classpath.tools.javah.Main if GNU classpath is used.