Python 3.10 regression: injector.UnknownProvider: couldn't determine provider

[leinardi]

Some users of Fedora 35 reported that an app I developed doesn't work anymore after upgrading from Fedora 43.

After some investigation it seems related to the upgrade to Python 3.10. I was able to reproduce the same issue on Ubuntu 21.10 after installing Python 3.10 and running the app on a venv that uses it.

This is the relevant traceback:

Traceback (most recent call last):
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 658, in get_binding
    return self._get_binding(interface, only_this_binder=is_scope)
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 653, in _get_binding
    raise KeyError
KeyError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/leinardi/Workspace/gitlab/gwe/.pycharm/gwe", line 43, in <module>
    from gwe import __main__
  File "/home/leinardi/Workspace/gitlab/gwe/gwe/__main__.py", line 33, in <module>
    from gwe.model.current_fan_profile import CurrentFanProfile
  File "/home/leinardi/Workspace/gitlab/gwe/gwe/model/__init__.py", line 19, in <module>
    from gwe.model.overclock_profile import OverclockProfile
  File "/home/leinardi/Workspace/gitlab/gwe/gwe/model/overclock_profile.py", line 29, in <module>
    OVERCLOCK_PROFILE_CHANGED_SUBJECT = INJECTOR.get(OverclockProfileChangedSubject)
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 952, in get
    binding, binder = self.binder.get_binding(interface)
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 667, in get_binding
    binding = self.create_binding(interface)
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 582, in create_binding
    provider = self.provider_for(interface, to)
  File "/home/leinardi/Workspace/gitlab/gwe/venv/lib/python3.10/site-packages/injector/__init__.py", line 644, in provider_for
    raise UnknownProvider('couldn\'t determine provider for %r to %r' % (interface, to))
injector.UnknownProvider: couldn't determine provider for gwe.di.OverclockProfileChangedSubject to None

The code that is triggering the issue is this one:

OVERCLOCK_PROFILE_CHANGED_SUBJECT = INJECTOR.get(OverclockProfileChangedSubject)

where OverclockProfileChangedSubject is defined as:

OverclockProfileChangedSubject = NewType('OverclockProfileChangedSubject', Subject)

This code worked fine for several versions of Python and version 3.10 seems to be the only one affected.

[leinardi]

Is there any know workaroud (beside downgrading Python) for this issue?

[leinardi]

@jstasiak any suggestion?

[marvic2409]

Yep this issue is also affecting me.

[jstasiak]

No suggestions, sorry, pull requests fixing this are welcome though.

PS. Please provide the exact Python and Injector versions where this happens, for clarity.

[gardotd426]

This is now also an issue on Arch Linux, as it's been moved to 3.10 as well. It's going to be an issue everywhere eventually.

[Lamieur]

PS. Please provide the exact Python and Injector versions where this happens, for clarity.

On Fedora 35 I've tested:

• Python 3.10.0 and Injector 0.18.4 (latest release)
• Python 3.10.0 and current git master branch of Injector,
• Python 3.10.1 (currently in updates-testing) and current git of Injector.

All these with gwe's git.

Every combination gives the same result.

[d4mler]

Same problem on Arch.

[WickedLukas]

I found this issue with a similar error message and appearently someone also found a solution for it : #175
Unfortunately I am not knowledgeable enough, but maybe someone else can review it.

[Lamieur]

No, #175 is unrelated. I had the same thought as you, so when I was testing with git branch of injector (my previous comment), I have in fact rebuilt injector with #188 - that didn't do a thing for our case. It was faster to check than to think on what Injector does or what Subject is, but apparently it's not "generic", whatever that is! ;)

Anyways, this is completely different, a regression caused by something in Python 3.10 for something which worked before.

(or RxPY 3.2.0, as that was on 3.1.1 in Fedora 34. 3.1.1 doesn't build with Python 3.10 so I can't check :))

[gardotd426]

RxPY was on 3.2.0 on Arch before Arch moved to 3.10, and this issue wasn't present, so it's not RxPY.

[Lamieur]

Good to know, I wanted to confirm but couldn't easily, thanks :)

[leinardi]

@jstasiak please have a look at #193

[leinardi]

@jstasiak Thank you for merging the fix 👍

Is there an ETA for the next release that will include this fix?

[gardotd426]

@leinardi I will say that I installed python-injector-git from the AUR (I had to edit the PKGBUILD because the writer of it has it in a broken state but it was a quick fix) and after installing that, GWE works perfectly.

[abend-arg]

Just did exactly the same as @gardotd426. Edited the PKGBUILD in order to solve the issue. GWE started to work again. The hotfix did it.

[gardotd426]

It's no longer needed, after I reported the issue, the maintainer updated the PKGBUILD so all is good now. No editing of PKGBUILDs necessary. So anyone not able to wait can just use python-injector-git from the AUR (if they're on an Arch-based distro). Beyond that, I'd say this is probably venturing into off-topic territory from here on out

[jstasiak]

@jstasiak Thank you for merging the fix 👍

Is there an ETA for the next release that will include this fix?

No worries. It's just been released as version 0.19.0, enjoy.