Error registering addons disabled by Load Factory Settings (from preferences window) #67577

New Issue

Ryan Inch · 2019-07-24T09:32:12+02:00

Ryan Inch commented

2019-07-24 09:32:12 +02:00

System Information
Operating system: Arch Linux 64 bit
Graphics card: Nvidia 660m

Blender Version
Broken: 2.80rc2, 2.83 beta (c57f65c088)

Short description of error
Load Factory Settings resets addon preferences before addons have a chance to unregister

Exact steps for others to reproduce the error

Enable the Collection Manager add-on.
In the 3D Viewport, see that there are a bunch of crosses in the top-right corner.
Load Factory Settings.
See that in the 3D Viewport the crosses have not disappeared; the add-on was unsuccessfully unregistered.
Try enable Collection Manager again, it will produce an error that a class is already registered.

During unregistering, this error occurs:

Exception in module unregister(): '/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/addons/object_collection_manager/__init__.py'
Traceback (most recent call last):
  File "/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/modules/addon_utils.py", line 434, in disable
    mod.unregister()
  File "/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/addons/object_collection_manager/__init__.py", line 149, in unregister
    if bpy.context.preferences.addons[__package__].preferences.enable_qcd:
KeyError: 'bpy_prop_collection[key]: key "object_collection_manager" not found'
	addon_utils.reset_all unloading blender_cloud

**System Information** Operating system: Arch Linux 64 bit Graphics card: Nvidia 660m **Blender Version** Broken: 2.80rc2, 2.83 beta (c57f65c088) **Short description of error** Load Factory Settings resets addon preferences before addons have a chance to unregister **Exact steps for others to reproduce the error** 1. Enable the Collection Manager add-on. 2. In the 3D Viewport, see that there are a bunch of crosses in the top-right corner. 3. Load Factory Settings. 4. See that in the 3D Viewport the crosses have not disappeared; the add-on was unsuccessfully unregistered. 5. Try enable Collection Manager again, it will produce an error that a class is already registered. During unregistering, this error occurs: ``` Exception in module unregister(): '/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/addons/object_collection_manager/__init__.py' Traceback (most recent call last): File "/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/modules/addon_utils.py", line 434, in disable mod.unregister() File "/home/sybren/workspace/blender-git/build_linux/bin/2.83/scripts/addons/object_collection_manager/__init__.py", line 149, in unregister if bpy.context.preferences.addons[__package__].preferences.enable_qcd: KeyError: 'bpy_prop_collection[key]: key "object_collection_manager" not found' addon_utils.reset_all unloading blender_cloud ```

Ryan Inch commented

2019-07-24 09:32:12 +02:00

Added subscriber: @Imaginer

Gavin Scott commented

2019-07-24 12:37:30 +02:00

Added subscriber: @GavinScott

Gavin Scott commented

2019-07-24 12:37:30 +02:00

Happens on Windows as well. I get problems with some but not all addons. After enabling add-ons, then Loading Factory Settings the addons show as disabled but attempting to enable them results in various errors suggesting that the Load Factory Settings did not un-register them but did disable them.

Gavin Scott commented

2019-07-24 12:43:24 +02:00

Workaround is to exit Blender and start with --factory-startup

Germano Cavalcante changed title from ~~Load Factory Settings resets addon preferences to early~~ to Error registering addons disabled by Load Factory Settings (from preferences window)

2019-07-24 17:45:49 +02:00

Campbell Barton was assigned by Germano Cavalcante

2019-07-24 17:45:49 +02:00

Campbell Barton was unassigned by Dalai Felinto

2019-12-23 16:33:34 +01:00

Dalai Felinto commented

2019-12-23 16:33:34 +01:00

Added subscriber: @ideasman42

Sybren A. Stüvel commented

2020-01-27 18:03:32 +01:00

Added subscriber: @dr.sybren

Sybren A. Stüvel commented

2020-01-27 18:03:32 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Sybren A. Stüvel closed this issue

2020-01-27 18:03:32 +01:00

Sybren A. Stüvel self-assigned this 2020-01-27 18:03:32 +01:00

Sybren A. Stüvel commented

2020-01-27 18:03:32 +01:00

I cannot reproduce this with the latest Blender release (2.81a), so this appears to have been fixed already.
If the problem is still there with the latest Blender version, please let us know in a comment, including how to reproduce the issue with that version.

I cannot reproduce this with the latest Blender release (2.81a), so this appears to have been fixed already. If the problem is still there with the latest Blender version, please let us know in a comment, including how to reproduce the issue with that version.

Ryan Inch commented

2020-04-07 23:27:41 +02:00

Sorry for the late reply, but I can confirm the underlying issue here hasn't been fixed. The reason Magic UV works now is because the code trying to access the preferences in the unregister function wasn't actually needed and was removed with commit: blender/blender-addons@ba7e0de977. This bug can now be reproduced with the object_collection_manager addon (mine).

Sybren A. Stüvel commented

2020-05-07 10:14:24 +02:00

Changed status from 'Resolved' to: 'Confirmed'

Sybren A. Stüvel reopened this issue

2020-05-07 10:14:24 +02:00

Ryan Inch commented

2020-05-07 10:21:36 +02:00

Thanks @dr.sybren !

Sybren A. Stüvel commented

2020-05-07 10:32:04 +02:00

@ideasman42 I have reopened this task as @Imaginer provided a new way to reproduce it (and I could reproduce it indeed). Do you know if access to bpy.context.preferences.addons[__package__] is guaranteed to work? In other words, is this an issue with Blender (i.e. something that should exist doesn't) or is it an issue with the add-on (i.e. accessing something that isn't guaranteed to exist)?

From what I can see, Blender does the following when loading factory settings:

Load the startup blend file.
Load the default preferences.
Iterate over all add-ons, and disable/enable them so that their state matches the current (so default) preferences.

One of the issues why this is not just a matter of accessing bpy.context.preferences.addons[__package__] is that the add-on tries to unregister submodules based on the user preferences:

    if bpy.context.preferences.addons[__package__].preferences.enable_qcd:
        qcd_init.unregister_qcd()

Of course if the unregister() function is called after the user preferences have been reset, this is no longer possible. I do something similar with the Blender Cloud add-on: when the current Cloud project is set up for Attract, it registers a handler so that I can draw on the VSE, and this handler of course has to be unregistered when unloading. If the user preferences are reset at that time, it won't have any current Cloud project, so it wouldn't known it has to unregister that draw handler.

It could also be argued that unregistration should always be complete, and should not rely on the user preferences at all. I'd be fine with this too, but that would require proper documentation; currently the reference doc for bpy.context.preferences.addons doesn't mention this.

@ideasman42 I have reopened this task as @Imaginer provided a new way to reproduce it (and I could reproduce it indeed). Do you know if access to `bpy.context.preferences.addons[__package__]` is guaranteed to work? In other words, is this an issue with Blender (i.e. something that should exist doesn't) or is it an issue with the add-on (i.e. accessing something that isn't guaranteed to exist)? From what I can see, Blender does the following when loading factory settings: - Load the startup blend file. - Load the default preferences. - Iterate over all add-ons, and disable/enable them so that their state matches the current (so default) preferences. One of the issues why this is not just a matter of accessing `bpy.context.preferences.addons[__package__]` is that the add-on tries to unregister submodules based on the user preferences: ``` if bpy.context.preferences.addons[__package__].preferences.enable_qcd: qcd_init.unregister_qcd() ``` Of course if the `unregister()` function is called after the user preferences have been reset, this is no longer possible. I do something similar with the Blender Cloud add-on: when the current Cloud project is set up for Attract, it registers a handler so that I can draw on the VSE, and this handler of course has to be unregistered when unloading. If the user preferences are reset at that time, it won't have any current Cloud project, so it wouldn't known it has to unregister that draw handler. It could also be argued that unregistration should always be complete, and should not rely on the user preferences at all. I'd be fine with this too, but that would require proper documentation; currently [the reference doc for bpy.context.preferences.addons](https://docs.blender.org/api/master/bpy.types.Addons.html#bpy.types.Addons) doesn't mention this.

Sybren A. Stüvel removed their assignment 2020-05-08 11:40:04 +02:00

Campbell Barton self-assigned this 2020-05-08 13:58:53 +02:00

Ryan Inch commented

2020-05-26 07:40:01 +02:00

Any update on this? I'm really trying not to be pushy and I'm sure you have lots of things to deal with, but I'd prefer it if my addon wasn't released with blender 2.83 (LTS) with a bug where loading factory settings completely breaks it.