Printing labels

[gpetrom]

Hi

First thanks for the wonderful program.
I have setup inventree with docker latest stable edition

Python paths:
Executable  /usr/local/bin/python
Environment /usr/local

Installation paths:
Base        /home/inventree
Config      /home/inventree/data/config.yaml
Media       /home/inventree/data/media
Static      /home/inventree/data/static

Versions:
Python      3.11.9
Django      4.2.17
InvenTree   0.17.5
API         294
Node        N/A
Yarn        N/A

In system information
Plugin support enabled
Server status healthy

The problem is with printing labels

I have installed brother plugin and it says that is enabled. When i go inside the plugin i am seeing
the following
Version: 1.0.0
Enabled: Yes
Path: /usr/local/lib/python3.11/site-packages/inventree_brother/brother_plugin.py
Builtin: No
Package: No

I have added a brother machine
Initialized: Yes
Active: yes
Status: Connected
Errors: No errors reported

Then i have added a simple custom template below the code

{% extends "label/label_base.html" %}

{% block style %}
<!-- You can write custom CSS here -->
<style>
    @page {
        height: 12mm;
        padding: 1mm;
    margin: 0px 0px 0px 0px;
    }

    .location {
        padding: 5px;
        font-weight: bold;
        font-family: Arial, Helvetica, sans-serif;
        height: 100%;
        vertical-align: middle;
        float: right;
        display: inline;
        font-size: 125%;
        position: absolute;
        top: 0mm;
        left: 23mm;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
</style>

{% endblock %}

{% block content %}
<div class='location'>
    {{ location.name }}
</div>
{% endblock %}

When i am trying to print a location i am getting the following error

Type:
PicklingError
Path:
InvenTree.offload_task
Info:
Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver
When:
Feb. 3, 2025, 9:06 a.m.
Data:
Traceback (most recent call last):

File "/home/inventree/src/backend/InvenTree/InvenTree/tasks.py", line 208, in offload_task
task.run()

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 730, in run
self.id = async_task(self.func, *self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 71, in async_task
pack = SignedPackage.dumps(task)
^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 16, in dumps
return signing.dumps(
^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 152, in dumps
return TimestampSigner(key=key, salt=salt).sign_object(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 250, in sign_object
data = serializer().dumps(obj)
^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 36, in dumps
return pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

_pickle.PicklingError: Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver

Any ideas why is this happening what am i missing

One more question maybe it is related
When i am trying to print for example a report in pdf i am always redirected to the home page show me the parts but it does not generates any pdf.

Thanks in advanced

[SchrodingersGat]

@wolflu05 was this the same error you were seeing?

[wolflu05]

@SchrodingersGat not sure, haven't seen this exact one before.

@gpetrom are you using the redis cache?

[gpetrom]

First i was trying without redis then i installed redis also and same thing happens

[gpetrom]

The problem with pdf printing is not related with the problem with printing in brother printer

[dieselburner]

Today I was about to print some labels for delivered components when I hit this error as well.

Type:

PicklingError

Path:

InvenTree.offload_task

Info:

Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver

Data:

Traceback (most recent call last):

File "/home/inventree/src/backend/InvenTree/InvenTree/tasks.py", line 208, in offload_task
task.run()

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 730, in run
self.id = async_task(self.func, *self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/tasks.py", line 71, in async_task
pack = SignedPackage.dumps(task)
^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 16, in dumps
return signing.dumps(
^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 152, in dumps
return TimestampSigner(key=key, salt=salt).sign_object(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django/core/signing.py", line 250, in sign_object
data = serializer().dumps(obj)
^^^^^^^^^^^^^^^^^^^^^^^

File "/root/.local/lib/python3.11/site-packages/django_q/signing.py", line 36, in dumps
return pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

_pickle.PicklingError: Can't pickle <class 'inventree_brother.brother_plugin.BrotherLabelPrinterDriver'>: it's not the same object as inventree_brother.brother_plugin.BrotherLabelPrinterDriver

Please let me know if you need more info.

[dieselburner]

Also, one interesting thing which I've found: in new platform interface under Machines settings (https://inventree/platform/settings/admin/machine/) I see ten repeated Machine Errors:

Registry Registry Errors
There are machine registry errors
- Cannot re-register driver 'brother'
- ...

[dieselburner]

Info about my instance:

# Version Information:
InvenTree-Version: 0.17.5
Django Version: 4.2.17
Commit Hash: 0f9bddb
Commit Date: 2025-02-03

Database: postgresql
Debug-Mode: False
Deployed using Docker: True
Platform: Linux-6.8.0-1018-raspi-aarch64-with
Installer: DOC

Active plugins: [{'name': 'InvenTreeBarcode', 'slug': 'inventreebarcode', 'version': '2.1.0'}, {'name': 'InvenTreeCoreNotificationsPlugin', 'slug': 'inventreecorenotificationsplugin', 'version': '1.0.0'}, {'name': 'InvenTreeCurrencyExchange', 'slug': 'inventreecurrencyexchange', 'version': '1.0.0'}, {'name': 'InvenTreeLabel', 'slug': 'inventreelabel', 'version': '1.1.0'}, {'name': 'InvenTreeLabelMachine', 'slug': 'inventreelabelmachine', 'version': '1.0.0'}, {'name': 'InvenTreeLabelSheet', 'slug': 'inventreelabelsheet', 'version': '1.0.0'}, {'name': 'DigiKeyPlugin', 'slug': 'digikeyplugin', 'version': '1.0.0'}, {'name': 'LCSCPlugin', 'slug': 'lcscplugin', 'version': '1.0.0'}, {'name': 'MouserPlugin', 'slug': 'mouserplugin', 'version': '1.0.0'}, {'name': 'TMEPlugin', 'slug': 'tmeplugin', 'version': '1.0.0'}, {'name': 'Brother Labels', 'slug': 'brother', 'version': '1.0.0'}, {'name': 'KiCadLibraryPlugin', 'slug': 'kicad-library-plugin', 'version': '1.4.3'}]

It's running in Docker, with connection to external PostgreSQL and Redis services.

[SchrodingersGat]

@dieselburner have you previously been able to print labels without issue? And have you also recently updated?

[dieselburner]

@SchrodingersGat Yes, last time I used label printer without issue was 2-3 months ago.
One important thing I should notice - I moved docker container to another machine and switched from SQLite to PostgreSQL + Redis, as I mentioned earlier. To be honest I don't remember if I checked if label printer is working after the move and database migration.
Should I try removing brother plugin and deleting its configuration, and reconfiguring it again from scratch?

[dieselburner]

I have played a bit around this label printing issue, and here's my result:

• Stopped and deleted inventree-server and inventree-worker containers
• Deleted contents of plugins.txt, made sure this file is passed as read-write to both server and worker:
  - ./conf/plugins.txt:/home/inventree/config/plugins.txt:rw
• Started containers fresh, docker compose up -d
• Followed plugin installation process as described in Plugins installation improvements #8503

Still receiving the same error message as per above.

[dieselburner]

Also, disabled Redis cache and removed following from configuration:

INVENTREE_CACHE_ENABLED=True
INVENTREE_CACHE_HOST=192.168.0.123
INVENTREE_CACHE_PORT=6379

Didn't helped.

[dieselburner]

Surprisingly, KiCad plugin works all the time. In my case (have two plugins installed- inventree-brother-plugin and inventree-kicad-plugin), only the Brother printer plugin misbehaves.

[dieselburner]

Is there anything I can help with to debug this issue further?

[dieselburner]

I have a docker compose file which points plugins.txt to a file with following contents:

inventree-brother-plugin
inventree-kicad-plugin

Also, I tried recently to feed this file as empty read-write file, and tried to manually install both of these plugins via web interface, but the behavior is the same: same error, same result.

[dieselburner]

Also, I see this commit which was committed 4 days ago, but to be honest cannot see what exactly it fixes. I'm no Python expert, but no newbie either, perhaps line breaks really fixes something.

[simonkuehling]

hmm, no idea regarding the commit either - maybe the commit is incomplete?
@SchrodingersGat can you chime in on that commit?

[SchrodingersGat]

Regarding the commit in question it fixes a bug whereby if the plugin did not have a before_printing method defined, then the print_labels method would be skipped also. It is a bug in the control flow due to the wrong indent on the changed code.

[simonkuehling]

Ooh, right, totally missed the changed indent 🤦‍♂️

[SchrodingersGat]

@gpetrom @simonkuehling regarding these printing errors - are you using the "old" user interface for label printing, or the new react-based UI?

[simonkuehling]

For me I purely run the new UI..

[gpetrom]

@gpetrom @simonkuehling regarding these printing errors - are you using the "old" user interface for label printing, or the new react-based UI?

I have tried both interfaces old and new

[dieselburner]

@SchrodingersGat I can't see in the release notes whether this particular issue was fixed in latest release or not. Is it?

[SchrodingersGat]

@dieselburner the fix was merged in #9191 - but it looks like that has not made it into 0.17.x

I will have to manually back-port that fix and issue a new release. I'll look into that.

[SchrodingersGat]

Ref: #9298