httk.workflow.errors
====================

.. py:module:: httk.workflow.errors

.. autoapi-nested-parse::

   Define exceptions raised by :mod:`httk.workflow`.



Exceptions
----------

.. autoapisummary::

   httk.workflow.errors.SealedError
   httk.workflow.errors.SealError
   httk.workflow.errors.WorkflowError
   httk.workflow.errors.ResolutionMiss
   httk.workflow.errors.FormatError
   httk.workflow.errors.WorkspaceUnavailableError
   httk.workflow.errors.WorkspaceCorruptionError
   httk.workflow.errors.TransitionLostError
   httk.workflow.errors.UnsupportedExtensionError
   httk.workflow.errors.TransactionError
   httk.workflow.errors.RunnerResolutionError


Module Contents
---------------

.. py:exception:: SealedError

   Bases: :py:obj:`RuntimeError`


   An action was refused because the subject, or its enclosure, is sealed.

   Changing a project's members while the project is sealed is refused rather
   than silently allowed: a seal a project commits to must not change beneath
   it.


.. py:exception:: SealError

   Bases: :py:obj:`RuntimeError`


   A seal cannot be written or verified.

   This is the *cannot proceed* failure: no signing key is available, or a
   member a project seal must cover is itself unsealed or has no handler. It
   never means an action was refused because something was already sealed; that
   is :class:`SealedError`.


.. py:exception:: WorkflowError

   Bases: :py:obj:`RuntimeError`


   Base class for workflow protocol failures.


.. py:exception:: ResolutionMiss

   Bases: :py:obj:`ValueError`


   A name did not resolve, without indicating malformed configuration.


.. py:exception:: FormatError

   Bases: :py:obj:`WorkflowError`, :py:obj:`ValueError`


   A workspace, job, journal frame, outcome, or request is malformed.


.. py:exception:: WorkspaceUnavailableError

   Bases: :py:obj:`WorkflowError`


   The workspace cannot currently provide a coherent protocol view.


.. py:exception:: WorkspaceCorruptionError

   Bases: :py:obj:`WorkflowError`


   The authoritative filesystem state is internally inconsistent.


.. py:exception:: TransitionLostError

   Bases: :py:obj:`WorkflowError`


   Another actor committed a transition from the expected marker.


.. py:exception:: UnsupportedExtensionError

   Bases: :py:obj:`WorkflowError`


   A workspace requires an extension this implementation does not support.


.. py:exception:: TransactionError

   Bases: :py:obj:`WorkflowError`


   A transactional-data manifest cannot be safely replayed.


.. py:exception:: RunnerResolutionError(code, message)

   Bases: :py:obj:`WorkflowError`


   A shared runner cannot be resolved or verified.

   The failure carries the exact protocol failure ``code`` the manager records,
   so an unresolvable runner (``runner_unavailable``), a runner whose bytes
   disagree with the digest the job pinned (``runner_mismatch``), a
   missing registration (``runner_not_built``), and a failed foreground build
   (``runner_build_failed``) stay distinguishable to an operator.

   :param code: Protocol failure code recorded by the manager.
   :param message: Human-readable failure description.


   .. py:attribute:: code