$ PYTHONIOENCODING= ./python
Fatal Python error: Py_Initialize: can't initialize sys standard streams
LookupError: unknown encoding: 
Aborted (core dumped)

As a consequence we can't set only the error handler.

$ PYTHONIOENCODING=:surrogateescape ./python
Fatal Python error: Py_Initialize: can't initialize sys standard streams
LookupError: unknown encoding: 
Aborted (core dumped)

Here is a patch which allows accepting empty encoding as default encoding.