PyQt5 and Big Sur

[Phil Thompson]

Note that PyQt v5.15.2 will set this automatically.

Phil

On 17/11/2020 14:16, Eric Larson wrote:
> Beautiful, QT_MAC_WANTS_LAYER=1 works for me!
> 
> Eric
> 
> 
> On Tue, Nov 17, 2020 at 8:33 AM Marius Shekow <
> marius.shekow at fit.fraunhofer.de> wrote:
> 
>> Hi, I also found that setting the environment variable
>> QT_MAC_WANTS_LAYER to "1" fixes the problem, as per
>> 
>> https://stackoverflow.com/questions/64818879/is-there-any-solution-regarding-to-pyqt-library-doesnt-work-in-mac-os-big-sur/64856281
>> 
>> No idea, why it works, but it's a good workaround for your early 
>> adoper
>> users who accuse you, the app developer, to have "broken everything".
>> Shame on me... (sarcasm).
>> 
>> Am 15.11.2020 um 23:35 schrieb Jeremy Katz:
>> >
>> > On 15/Nov/20 04:50, Eric Larson wrote:
>> >> I recently updated to Big Sur (11.0.1). I have Qt5Agg set as my
>> >> matplotlib backend. Opening a matploltlib figure in interactive mode now
>> >> causes the interpreter to hang on 5.12 and 5.15.1. Even running a hello
>> >> world <https://pythonprogramminglanguage.com/pyqt5-hello-world/>
>> example
>> >> causes the interpreter to hang.
>> >>
>> >> I tried the same matplotlib code with pyside2, and there at least the
>> >> interpreter would not hang. For both PyQt5 and pyside2, however, no
>> >> window actually showed up, even though an icon did appear. So it seems
>> >> at least some of this is probably a problem at the level of Qt rather
>> >> than PyQt5.
>> > I had an apparent application hang with PyQt and Qt 5.15.0, and an
>> > application bundle created with PyInstaller. Dtruss revealed that the
>> > application was executing, but very slowly. IIRC, the main window went
>> > from displaying in ~5 seconds with macOS Catalina to 4 minutes with Big
>> Sur.
>> >
>> > Running the application once with "open -F" seemed to resolve the issue
>> > permanently.
>> >
>> --
>> Dr. Marius Shekow
>> Mixed and Augmented Reality Solutions, Fraunhofer FIT
>> http://www.fit.fraunhofer.de/mars
>> Tel.: +49(0)2241 - 14-3555
>> 
>>