I noticed the following behavior by running the test suite twice within the same octave session. It seems that you can't run the tests in fcn-handle-derived-resolution.tst before the tests in ctor-vs-method.tst.
It seems that octave keeps an instance of the @parent class from the first test series, and is then unable to instantiate a @parent object of the second test series, because of field mismatch. Using "clear all" didn't resolve the issue.
As a result, during the second run of the full test suites, 3/4 tests from ctor-vs-method.tst fail.
Michael.