ha.UnitOfFrequency.HERTZ error

[lutfijw]

after updating to the latest HomeAssistant stable version 2024.5.3, OCPP integration is failing due to unknown unit in const.py file.
I need to delete the ha.UnitOfFrequency.HERTZ due to it caused and error. Seem like Home Assistant is deleting the HERTZ unit.

[leonetnl]

Same issue here

[lutfijw]

As interim, you can delete the ha.UnitOfFrequency.HERTZ in const.py file and restart HA. Not sure if it will impact others functionalities but mine worked good. After restart, the integration successfully loaded.

[drc38]

Seems strange as UnitOfFrequency.HERTZ still exists in HA. Can you revert and post the error logs?

[martenjacobs]

@drc38 I'm having the same issue. I think this is due to the ocpp package having released 1.0.0, which doesn't have the hertz UoM anymore: https://github.com/mobilityhouse/ocpp/blob/1.0.0/ocpp/v16/enums.py#L713C7-L713C20
The full error (for me at least) is as follows:

---

Logger: homeassistant.loader
Source: loader.py:1041
First occurred: 21:41:15 (2 occurrences)
Last logged: 21:41:15

Unexpected exception importing component custom_components.ocpp
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/loader.py", line 1041, in _get_component
    ComponentProtocol, importlib.import_module(self.pkg_path)
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/util/loop.py", line 144, in protected_loop_func
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/config/custom_components/ocpp/__init__.py", line 13, in <module>
    from .api import CentralSystem
  File "/config/custom_components/ocpp/api.py", line 52, in <module>
    from .const import (
  File "/config/custom_components/ocpp/const.py", line 121, in <module>
    UnitOfMeasure.hertz: ha.UnitOfFrequency.HERTZ,
    ^^^^^^^^^^^^^^^^^^^
AttributeError: type object 'UnitOfMeasure' has no attribute 'hertz'

[drc38]

Thanks, the issue is with the ocpp library latest release see mobilityhouse/ocpp#207 rather than HA 2024.5.3. The fix is still the same :)