Such a policy file is useful when developing a benchmark (bugs <https://sourceforge.net/tracker/?func=detail&atid=861957&aid=3056006&group_id=172498> and <https://sourceforge.net/tracker/?func=detail&atid=861957&aid=3056019&group_id=172498> were found this way); if a benchmark reads files outside the scratch directory, for example, this manifests itself in a permission check.
Attached is a policy file that grants the harness the necessary permissions. It does not yet grant any permissions to a benchmark, however, as it is only meant as a template. Running the benchmark with such a policy is straight-forward:
java -Djava.security.manager -Djava.security.policy=dacapo.policy -Djava.security.debug=failed -jar dacapo-9.12-bach.jar