def on_remembered_identifiers_failure(self, exc, subject_context):
msg = ("<STR_LIT>"<EOL>"<STR_LIT>"<EOL>"<STR_LIT>"<EOL>"<STR_LIT>"<EOL>"<STR_LIT>", exc)<EOL>logger.debug(msg)<EOL>self.forget_identity(subject_context)<EOL>raise exc<EOL>
Called when an exception is thrown while trying to retrieve identifier.
The default implementation logs a debug message and forgets ('unremembers')
the problem identity by calling forget_identity(subject_context) and
then immediately re-raises the exception to allow the calling
component to react accordingly.

This method implementation never returns an object - it always rethrows,
but can be overridden by subclasses for custom handling behavior.

This most commonly would be called when an encryption key is updated
and old identifier are retrieved that have been encrypted with the
previous key.

:param exc: the exception that was thrown
:param subject_context: the contextual data that is being
                        used to construct a Subject instance
:raises:  the original Exception passed is propagated in all cases