Outside the sandbox, the following will correctly echo java.util.regex.Pattern
But when sandboxed, it barfs with RejectedAccessException: Scripts not permitted to use staticMethod org.codehaus.groovy.runtime.ScriptBytecodeAdapter bitwiseNegate java.lang.Object.
This is distinct to CPS-transformed code - if that's in a @NonCPS method or any other non-CPS sandboxed code, it works fine. Somehow we're misidentifying the ~/foo/ in sandboxed CPS code.
EDIT: Amending to include the fact that staticMethod java.util.regex.Pattern compile java.lang.String is not whitelisted. That should be fixed too.