closure.setDelegate(man)
            closure()

            jarOut.putNextEntry(newEntryWithFixedTime(JarFile.MANIFEST_NAME))
            man.write(jarOut)

            hasConfiguredManifest = true
            this
        }

        private static JarEntry newEntryWithFixedTime(String path) {
            return new JarEntry(path).tap {
                // setTimeLocal() is better but it is Java 9+.