Code review comment for lp://staging/~barry/ubuntu-system-image/test-fixes

looking at the test code, I see that the test relies on xz support in tarfile:

            # Check that for touch and pd the android hacks are executed
            target_obj = tarfile.open(
                os.path.join(self.config.publish_path, "pool",
                             "ubuntu-HASH.tar.xz"), "r:xz")

This appears to be newly-introduced behavior as part of Lukasz's latest change. However, your change disables the complete test_generate_file_cdimage_ubuntu() test, which is a very extensive test that tests many other aspects of the generator. We cannot reasonably disable this test as a whole on python2.7.