Re: QtPy (python3-qtpy) dependencies
Le jeudi 07 avril 2022 à 10:49 +0100, Julian Gilbey a écrit :
> > > At present, the Debian python3-qtpy package depends on 17
> > > python3-pyqt5* packages, which seems to be at odds with the
> > > intention
> > > of the package to be Qt-package agnostic. It seems that it would
> > > be
> > > cleaner for python3-qtpy to
> > > Recommends: python3-pyqt5 | python3-pyside2.qtcore
> > > or perhaps to Depends: on these, and then if any packages require
> > > any
> > > more functionality than that provided by python3-pyqt5 or
> > > python3-pyside2.qtcore, they should explicitly state the packages
> > > they
> > > depend on. But it seems strange that a package depending on
> > > python3-qtpy should automatically pull in
> > > python3-pyqt5.qttexttospeech, for example.
> >
> > Agreed. I suppose the PyQt5 ecosystem has grown since initial
> > submission. There are two issues here: hard or soft depends and to
> > which core packages.
> >
> > Regarding Depends vs Recommends, as you correctly stated before,
> > QtPy
> > is useless without a "backend" implementation. Which is why I chose
> > Depends with a choice of alternatives. This way, a client package
> > depending on QtPy would always get a default implementation, whilst
> > having the possibility to override it with its own (but then what's
> > the
> > point?).
>
> That makes a lot of sense as well. At present, it still seems that
> PyQt5 is the most standard, but I don't have much of evidence to back
> up that hunch.
The stats for PyPI downloads backs that up:
https://libraries.io/pypi/PyQt5
https://libraries.io/pypi/PySide2
I have a feeling this will turn differently for PyQt6 vs PySide6.
> > Regarding which packages to depend on, that's subject to which
> > subset
> > of Qt{5,6} is supported by QtPy today. These might be in a need for
> > an
> > update.
>
> It appears that PyQt6 isn't in Debian yet, so that's not really an
> option. Neither is PySide6, so it's just PyQt5 or PySide2.
>
In that case, there is not much else to do. Same status quo as last
time I contributed to the package.
> > > On the other hand, there are 13 packages in testing that depend
> > > on
> > > python3-qtpy, so they would potentially all require modifications
> > > to
> > > their dependencies if we made this change. (Three of these are
> > > "mine", but that still leaves 10 that are not.) I have not yet
> > > gone
> > > through all 13 to see what python3-pyqt5.* dependencies they
> > > actually
> > > have.
> >
> > I'd be in favour with the least invasive option, which is to still
> > use
> > QtPy with Depends on a default implementation but update it with
> > what's
> > available today.
>
> I'm happy with sticking with that. I still think we have too many
> dependencies, though; it's become rather a metapackage for PyQt5!
> But
> it's not a big deal.
That's the danger with these shim packages. If they don't capture the
same granularity of components as the backend implementations it wraps,
then it becomes a rather heavy and annoying metapackage.
Hope this helps.
Ghis
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