When a source file is deleted, the Ant Zip task does not remove it from the zip file. For example, suppose we have two files FileA and FileB, and we use an Ant Zip task to put them into a zip file File.zip. If we remove FileA and then run the zip task again, FileA will remain in File.zip, regardless of the value of the Zip task's "update" attribute.

This has created some problems in grading, as supposedly deleted files were still in csns.zip and caused compilation and other errors. So for future assignments, please modify (if necessary) the zip target of your build file so that it always deletes the old zip file before creating a new one. In other words, it should look like the following:

<target name="zip">

    <delete ...>

    <zip ...>

</target>