[Feature Request] Drop 3.8 support, confirm 3.13 support

[cretz]

Describe the solution you'd like

See #398 (PR #422) where we did this for 3.7/3.12. Can see the several things that were done there and similar should be done here.

[josh-berry]

I happened to discover by accident that grpcio does not yet support Python 3.13 because it apparently depends on some C APIs that have been removed. So it seems unlikely we'd be able to support it without updating grpcio (if a fix is available; it may already be)

[cretz]

grpcio is an optional dependency. We only added it because we do generate the gRPC stubs in the temporalio.api.workflowservice.v1.service_pb2_grpc and technically allow users to use that module if they want pure Python gRPC clients or servers even though we don't use it in the SDK. We do use it in tests to implement a custom gRPC server and figured "why not let users use the generated gRPC stuff too" in addition to protos. We may be able to remove this stuff if we have to (otherwise we may be able to upgrade it, it all depends on how old of a protobuf library we need to support).

[sciyoshi]

Tracebacks are currently broken in Python 3.13. The original traceback for an exception happening in a workflow is clobbered and instead the following error is shown:

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/_workflow.py", line 260, in _handle_activation
    completion = await asyncio.wait_for(
                 ^^^^^^^^^^^^^^^^^^^^^^^
        activate_task, self._deadlock_timeout_seconds
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^

  File "/usr/local/lib/python3.13/asyncio/tasks.py", line 507, in wait_for
    return await fut
           ^^^^^^^^^

  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/workflow_sandbox/_runner.py", line 160, in activate
    self._run_code(
    ~~~~~~~~~~~~~~^
        "with __temporal_importer.applied():\n"
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        __temporal_activation=act,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/workflow_sandbox/_runner.py", line 176, in _run_code
    exec(code, self.globals_and_locals, self.globals_and_locals)
    ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "<string>", line 2, in <module>

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/workflow_sandbox/_in_sandbox.py", line 81, in activate
    return self.instance.activate(act)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/_workflow_instance.py", line 411, in activate
    logger.warning(
    ~~~~~~~~~~~~~~^
        f"Failed activation on workflow {self._info.workflow_type} with ID {self._info.workflow_id} and run ID {self._info.run_id}",
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        exc_info=activation_err,
        ^^^^^^^^^^^^^^^^^^^^^^^^
        extra={"temporal_workflow": self._info._logger_details()},
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1531, in warning
    self._log(WARNING, msg, args, **kwargs)
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1664, in _log
    self.handle(record)
    ~~~~~~~~~~~^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1680, in handle
    self.callHandlers(record)
    ~~~~~~~~~~~~~~~~~^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1744, in callHandlers
    lastResort.handle(record)
    ~~~~~~~~~~~~~~~~~^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1026, in handle
    self.emit(record)
    ~~~~~~~~~^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1158, in emit
    self.handleError(record)
    ~~~~~~~~~~~~~~~~^^^^^^^^

  File "/usr/local/lib/python3.13/logging/__init__.py", line 1075, in handleError
    traceback.print_exception(exc, limit=None, file=sys.stderr)
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/usr/local/lib/python3.13/traceback.py", line 129, in print_exception
    te = TracebackException(type(value), value, tb, limit=limit, compact=True)

  File "/usr/local/lib/python3.13/traceback.py", line 1044, in __init__
    self.stack = StackSummary._extract_from_extended_frame_gen(
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        _walk_tb_with_full_positions(exc_traceback),
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        limit=limit, lookup_lines=lookup_lines,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        capture_locals=capture_locals)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

  File "/usr/local/lib/python3.13/traceback.py", line 492, in _extract_from_extended_frame_gen
    f.line

  File "/usr/local/lib/python3.13/traceback.py", line 369, in line
    self._set_lines()
    ~~~~~~~~~~~~~~~^^

  File "/usr/local/lib/python3.13/traceback.py", line 350, in _set_lines
    lines.append(linecache.getline(self.filename, lineno).rstrip())
                 ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^

  File "/usr/local/lib/python3.13/linecache.py", line 25, in getline
    lines = getlines(filename, module_globals)

  File "/usr/local/lib/python3.13/linecache.py", line 41, in getlines
    return updatecache(filename, module_globals)

  File "/usr/local/lib/python3.13/linecache.py", line 100, in updatecache
    stat = os.stat(fullname)

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/workflow_sandbox/_restrictions.py", line 964, in __call__
    state.assert_child_not_restricted("__call__")
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^

  File "/code/.venv/lib/python3.13/site-packages/temporalio/worker/workflow_sandbox/_restrictions.py", line 792, in assert_child_not_restricted
    raise RestrictedWorkflowAccessError(
        f"{self.name}.{name}", override_message=matcher.leaf_message
    )

The error message occurs from an attempt to access linecache inside the original exception, leading to this:

Cannot access os.stat.__call__ from inside a workflow. If this is code from a module not used in a workflow or known to only be used deterministically from a workflow, mark the import as pass through.

[cprafullchandra]

Hi, I am still seeing this issue.

temporalio.worker.workflow_sandbox._restrictions.RestrictedWorkflowAccessError: Cannot access os.stat.__call__ from inside a workflow. If this is code from a module not used in a workflow or known to only be used deterministically from a workflow, mark the import as pass through.

Python = 3.13.0
temporalio = 1.9.0
temporal (server) = 1.2.0

Reverting to Python 3.12 fixed the tracebacks so I could see the actual error.

[FatihKartal]

Also facing what @cprafullchandra mentioned when hosting our workers for Temporal cloud. I hope this can be resolved soon as we are locked into Python 3.13. currently.

[cretz]

3.13 support is in the next release (should not be too long now, though no exact timelines)