Issue2483

PyObject implements Serializable, but it does not define a serialVersionUID.

As its serialized form has changed and the serialVersionUID is automatically generated, PyObject or any subclass serialized with Jython 2.5 is no longer readable with Jython 2.7.

Possibly adding this explicit serialVersionUID to PyObject in Jython 2.7 could solve the issue:

private static final long serialVersionUID = -5518487409570819225L;

We could not try it because org.python.core.PyObject is a special class in the sense that it needs to be compiled with a custom compiler that takes into account annotations to generate auxiliary classes.

Any fix or workaround would be welcome.

Agreed, we should add the serialVersionUID here. Using 2.5's version sounds reasonable. I expect, without actually trying it out, that changes to PyObject should be backwards compatible to 2.5, and forward compatible to 2.7.

Revisit for possible inclusion in 2.7.1

Let's revisit in 2.7.2 - I'm not sure of the nuances here, and especially of the stability of the contract this is committing Jython (and its developers) to for PyObject and its subclasses.