[FIXED] No compatibility with PyModbus of upcoming 2025.9 release

[jacauc]

This is probably known, but I did not find any existing issue for this.
Integration fails to startup with HA 2025.9.b0 likely due to PyModbus API changes.
Failed setup, will retry: ModbusClientMixin.read_holding_registers() got an unexpected keyword argument 'slave'

Environment

• Home Assistant Core release with the issue: 2025.9.b0
• Last working Home Assistant Core release (if known): 2025.8.3
• Integration version causing this issue: 0.6.1

Problem-relevant configuration dialog

Traceback/Error logs

In case of unit ID issue, missing devices or non-updating devices

Additional information

[roberto-Jade]

I had to change hub.py:
return self._client.write_register(address=address, value=value, slave=slave)
To:
return self._client.write_register(address=address, value=value, device_id=slave)

And this:
return self._client.read_holding_registers(
address=address, count=count, slave=slave
)
To:
return self._client.read_holding_registers(
address=address, count=count, device_id=slave
)

[jacauc]

Yep, that's exactly what my PR does which is linked above

[sfstar]

To anyone reading this:
The changes made by @jacauc have been merged and preparations have been made to get a bugfix release ready.
In order to not get any conflicts with the 0.7.0 beta the changes for that release have been reverted and the 0.6.2 bugfix release will be released once it is tested.
I expect that this will be done by tuesday the latest so that the release on wednesday won't result in broken installs for users of this integration.

Thank you @jacauc for bringing this to my attention and proposing a pr.

For anyone looking to update:
The 0.6.2 release will include a hacs.json bump in order to mark 2025.9 as the latest compatible release of ha core.
I believe that Hacs should not allow you to install the upcoming 0.6.2 patch release of this integration unless you are running 2025.9.
Although I'm not 100% sure.
If you are able to upgrade this integration while not running 2025.9 then please attempt to combine it with the 2025.9 release as other modbus integrations and the core modbus integration will break if this integration is bumped seperately.

For users running multiple modbus integrations it is recommended to check for each of the modbus integrations if they are compatible with the 2025.9 release of homeassistant and if not wait with the bump to 2025.9 until they are ready.

Please release/release notes:
https://github.com/sfstar/hass-victron/releases/tag/v0.6.2
Will be promoted to a non beta release once tested and 2025.9 ha core release is out.

[sfstar]

Change has been tested with local modbus entries in configuration file enabled on the ha core dev branch for 2025.9>
As far as I can see the release 0.6.2 will work with 2025.9 (with the core modbus addon also enabled).

Therefore, I promoted the release 0.6.2 to the latest release in preparation of the release of 2025.9 later this evening.
Users should still check if all other integrations that rely on modbus connections for other components have a release available that is compatible with 2025.9 before upgrading this integration and ha core.

[tpomerhn]

FYI, just updated to HA 2025.8.3 and HAOS 2025.8.3 and version 0.6.2 and am encountering the issue for this bug. So either it is not fully backward-compatible with pre-2025.9.x versions, or there is an update to September versions of PyModbus that are in the August updates that break this ahead of 0.7.0. So it would be good if we expedite this update into the production code.

[sfstar]

Thank you for your feedback.
I see that you are running ha core version 2025.8.3.
The 0.6.2 release is only compatible with ha core 2025.9.0 or higher.
This release was created 34 minutes ago and will soon be installable by end users:
https://github.com/home-assistant/core/releases/tag/2025.9.0

[tpomerhn]

Okay thanks, looks like 9.0 is accessible now in HA, updating now. Guess I was just in that limbo between 8.3 being the latest and 9.0's release, when 0.6.2 was the latest in the Victron integration. Looks like it's working now on 9.0 for me.

Would be good if in the future this kinda thing happens to put in an if/elif/else or try/except loop to handle versioning, if the value is handled the same but just named differently. But no matter now, it's working. Thanks for your work on this!

[mmaritz]

I am not getting the update for this fix. Upgrade to 2025.9.0 but no victron update gets displayed.
Is there an ETA on victron update? or a delay?

Will restore the backup.

Tx for the hard work on this @sfstar

[jacauc]

Try force checking for updates in Settings, System, Updates.

Came through just fine for me