[Bug 1631922] New: No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Bug ID: 1631922
           Summary: No text in Blender UI
           Product: Fedora
           Version: 29
         Component: blender
          Severity: high
          Assignee: [e-mail]
          Reporter: [e-mail]
        QA Contact: [e-mail]
                CC: [e-mail],
                    [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail]

Created attachment 1485834
  --> https://bugzilla.redhat.com/attachment.cgi?id=1485834&action=edit
Blender no text

Description of problem:
No text in UI.

Version-Release number of selected component (if applicable):
2.79b-7

How reproducible:
Run Blender.

Actual results:
No text and other UI elements. Blender unusable.

Expected results:
As before.

Additional info:
Blender from Steam and from official Blender site run ok.

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Luya Tshimbalanga  changed:

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                 CC|                            |[e-mail],
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              Flags|                            |needinfo?(ego.cordatus@gmai
                   |                            |l.com)

--- Comment #1 from Luya Tshimbalanga  ---
Hello Artem,

Would you start blender from the terminal and post the verbose message?

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Artem  changed:

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--- Comment #2 from Artem  ---
Created attachment 1486621
  --> https://bugzilla.redhat.com/attachment.cgi?id=1486621&action=edit
blender startup log

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #3 from Artem  ---
Sure. How could i can forget about this. I attached startup log
https://bugzilla.redhat.com/attachment.cgi?id=1486621

Something with Python probably.

Additional info if this could help: i am using nvidia-396.54-1.fc29.x86_64
driver from RPM Fusion.

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #4 from Nicolas Chauvet (kwizart)  ---
(In reply to Artem from comment #3)
...
> Additional info if this could help: i am using nvidia-396.54-1.fc29.x86_64
> driver from RPM Fusion.

I'm not reproducing with nvidia drivers.

Have you made a particular action, can you retry from a clean blender profile ?
(using a new account)?

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #5 from Artem  ---
(In reply to Nicolas Chauvet (kwizart) from comment #4)
> Have you made a particular action, can you retry from a clean blender
> profile ? (using a new account)?

Tried with new clean Blender profile - same issue.

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #6 from Nicolas Chauvet (kwizart)  ---
I should reproduce on f29, It was on f28...

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #7 from Artem  ---
(In reply to Nicolas Chauvet (kwizart) from comment #6)
> I should reproduce on f29, It was on f28...

My Blender on F28 was ok without this issue too. And after upgrade F28 to F29 i
got this.

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #8 from Luya Tshimbalanga  ---
It appears python 3.7 is currently incompatible with Blender 2.79a hence the
traceback.
https://blender.stackexchange.com/questions/115718/blender-as-python-module-...

Possible workaround is to rebuild against python36 for the time being. I will
work on it.

[Bug 1631922] No text in Blender UI

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Miro Hrončok  changed:

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                 CC|                            |[e-mail],
                   |                            |[e-mail],
                   |                            |[e-mail]
             Blocks|                            |1565020 (PYTHON37)
              Flags|                            |needinfo?([e-mail])

--- Comment #9 from Miro Hrončok  ---
Marcel, could you please look at this?

AFAIK you are highly qualified for both Blender and Python 3.7.

Thank you very much.

Referenced Bugs:

https://bugzilla.redhat.com/show_bug.cgi?id=1565020
[Bug 1565020] Python 3.7

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Luya Tshimbalanga  changed:

What    |Removed                     |Added
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            Summary|No text in Blender UI       |No text in Blender UI due
                   |                            |to bpy incompatible with
                   |                            |python 3.7

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Marcel Plch  changed:

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--- Comment #10 from Marcel Plch  ---
I am currently quite busy.
If nobody who'd like to take this on himself shows up in a few days, I'll
investigate this issue and try to bring up some solution.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #11 from Marcel Plch  ---
I was able to get quite far, but I have problems getting to the problem itself.
This will bring you to the point just before the first attribute error:

---------------
$ gdb blender
(gdb) br bpy_rna.c:7416
(gdb) r
---------------

What is failing here:
Blender initializes the python _bpy module (seemingly) without any problems. It
then imports the public bpy module (python layer) as a sanity check.
This import triggers registration of python-ized blender types. The
registration fails because it expects the type to have some attribute it
doesn't have.
This is very hard to debug because something fails silently here and the
registrations are scattered all over the code.

My suggestions what is going on:
*SOMEWHERE* in the code, some incompatibility occurs and
1. ... mangles flag that states if the attribute is optional.
2. ... mangles attribute that is being looked up.
3. Something totally different.

I suggest working with upstream, because this problem requires good knowledge
of both python and blender internals.

I need to pay attention to other matters now.
I'll hopefully be able to get back to this soon.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #12 from Luya Tshimbalanga  ---
Just got a result on Blender development:
https://developer.blender.org/search/query/uuadOfAnF6Df/#R

and found 
https://developer.blender.org/rB1db47a2ccd1e68994bf8140eba6cc2a26a2bc91f

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #13 from Petr Viktorin  ---
That commit has "TODO(campbell): Use Python3.7x _PyObject_LookupAttr()"

I hope the upstream developer is aware that this is private, experimental API,
which might be removed (or worse, change semantics) at any time.
It was added to Python here: https://github.com/python/cpython/pull/5222

I don't quite understand what the Blender code does. It would be useful to (get
the Blender dev) summarize the problem _PyObject_LookupAttr would solve, so
maybe it (or an even better API) can be bade public in Python 3.8.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Victor Stinner  changed:

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--- Comment #14 from Victor Stinner  ---
I agree that private functions should not be used in 3rd party code. The
Blender code was already wrong, it's just that Python 3.7 became more strict
and so Blender has to be fixed: call PyErr_Clear() to not "leak" an exception
since the exception wasn't handled properly.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #15 from Luya Tshimbalanga  ---
Filed bug on https://developer.blender.org/T56969

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Miro Hrončok  changed:

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--- Comment #16 from Miro Hrončok  ---
Blender upstream says "The Blender 2.79b release was built with Python 3.5.3.
There is no expectation that it runs with Python 3.7.". Maybe we need to
explain:

* that we build Blender in Fedora and not use prebuilt binaries
 * that Fedora updated Python to 3.7 and we rebuilt all stuff

Chances are upstream is not aware of how things work in Fedora.

Chances also are that upstream is not yet interested in Python 3.7 support and
in that case we might need to deal with this alone. However other distros might
be interested as well. CCing Matěj Cepl from openSUSE.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Luya Tshimbalanga  changed:

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                 CC|                            |[e-mail]

--- Comment #17 from Luya Tshimbalanga  ---
*** Bug 1638999 has been marked as a duplicate of this bug. ***

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #18 from Luya Tshimbalanga  ---
(In reply to Miro Hrončok from comment #16)
> Chances also are that upstream is not yet interested in Python 3.7 support
> and in that case we might need to deal with this alone. However other
> distros might be interested as well. CCing Matěj Cepl from openSUSE.

Fortunately, Blender upstream is investigating their codes due to the reveal
from #14.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #19 from Andrea Bruna  ---
(In reply to Luya Tshimbalanga from comment #18)
> Fortunately, Blender upstream is investigating their codes due to the reveal
> from #14.

Does anybody have any idea for a possible workaround for the time being, apart
downloading and using the prebuild binaries from Blender foundation?

It does not look we can rely on a swift solution upstream (that "normal
priority" assigned and the lack of any update of feedback ever since October
the 12th do not look very promising) and Fedora Blender package is essentially
unusable despite F29 Final being released a couple of days ago.

I would gladly help but, sadly, I am afraid I lack the (python) skills and
knowledge to be ever remotely helpful.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #20 from Miro Hrončok  ---
Another workaround is flatpak
https://flathub.org/apps/details/org.blender.Blender

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

--- Comment #21 from Petr Viktorin  ---
For an immediate fix, apply the patch from
https://developer.blender.org/rB1db47a2ccd1e68994bf8140eba6cc2a26a2bc91f

I've made a pull request for f29 here:
https://src.fedoraproject.org/rpms/blender/pull-request/2

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Luya Tshimbalanga  changed:

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             Status|NEW                         |ASSIGNED

--- Comment #22 from Luya Tshimbalanga  ---
(In reply to Petr Viktorin from comment #21)
> For an immediate fix, apply the patch from
> https://developer.blender.org/rB1db47a2ccd1e68994bf8140eba6cc2a26a2bc91f
>
> I've made a pull request for f29 here:
> https://src.fedoraproject.org/rpms/blender/pull-request/2

Pull merged. I successfully test the scratch and confirm the fix. Update coming
shortly.

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Luya Tshimbalanga  changed:

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                 CC|                            |[e-mail]

--- Comment #23 from Luya Tshimbalanga  ---
*** Bug 1638592 has been marked as a duplicate of this bug. ***

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Fedora Update System  changed:

What    |Removed                     |Added
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             Status|ASSIGNED                    |MODIFIED

--- Comment #24 from Fedora Update System  ---
YafaRay-3.3.0-13.fc29 blender-2.79b-9.fc29 has been submitted as an update to
Fedora 29. https://bodhi.fedoraproject.org/updates/FEDORA-2018-baaa0f8a07

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Fedora Update System  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|MODIFIED                    |ON_QA

--- Comment #25 from Fedora Update System  ---
YafaRay-3.3.0-13.fc29, blender-2.79b-9.fc29 has been pushed to the Fedora 29
testing repository. If problems still persist, please make note of it in this
bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here:
https://bodhi.fedoraproject.org/updates/FEDORA-2018-baaa0f8a07

[Bug 1631922] No text in Blender UI due to bpy incompatible with python 3.7

https://bugzilla.redhat.com/show_bug.cgi?id=1631922

Fedora Update System  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ON_QA                       |CLOSED
   Fixed In Version|                            |blender-2.79b-9.fc29
         Resolution|---                         |ERRATA
        Last Closed|                            |2018-11-04 01:51:47

--- Comment #26 from Fedora Update System  ---
YafaRay-3.3.0-13.fc29, blender-2.79b-9.fc29 has been pushed to the Fedora 29
stable repository. If problems still persist, please make note of it in this
bug report.