Printing labels #9020

gpetrom · 2025-02-03T09:34:33Z

gpetrom
Feb 3, 2025

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 · 2025-02-03T11:32:00Z

SchrodingersGat
Feb 3, 2025
Maintainer

@wolflu05 was this the same error you were seeing?

2 replies

wolflu05 Feb 3, 2025
Collaborator

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

@gpetrom are you using the redis cache?

gpetrom Feb 4, 2025
Author

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

gpetrom · 2025-02-03T16:02:12Z

gpetrom
Feb 3, 2025
Author

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

0 replies

dieselburner · 2025-02-14T17:04:36Z

dieselburner
Feb 14, 2025

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.

2 replies

dieselburner Feb 14, 2025

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 Feb 14, 2025

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 · 2025-02-15T00:58:24Z

SchrodingersGat
Feb 15, 2025
Maintainer

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

4 replies

dieselburner Feb 15, 2025

@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 Feb 16, 2025

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 Feb 16, 2025

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 Feb 16, 2025

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 · 2025-02-18T13:47:15Z

dieselburner
Feb 18, 2025

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

10 replies

dieselburner Feb 25, 2025

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 Feb 25, 2025

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 Feb 25, 2025

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

SchrodingersGat Feb 26, 2025
Maintainer

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.