Bug#1148460: pandas: FTBFS against python 3.15rc2 as default

[Stuart Prescott]

Hi Rebecca

> The actual error in that log names the uninstallable package as 
> python3-pyqt5 (which possibly can't be made optional because of 
> #1119724), not any of these known-issue packages. 

Reading through #1119724 that looks like one of the various iterations 
of python3-pytestqt's dependencies...

The current situation is that pytestqt needs:

- some sort of Qt library installed (that can be pyqt5, pyqt6 or
   pyside6)

- the relevant split-packages installed for Qt6; these aren't monolithic
   packages any more and that might help avoid pandas having dependencies
   that aren't widely available

- configuration on which of the Qt APIs to use. This can be done either
   via the PYTEST_QT_API environment variable (from d/rules, d/tests/*)
   or by setting the pytest config option qt_api in pytest.ini or
   pyproject.toml.

This last option is particularly important for packaging; many upstreams 
that use pytestqt set up their test harness to iterate over the APIs and 
so leave it to pytestqt's automatic API detection to work out which one 
is installed and use that. That works on CI using tox, but doesn't work 
so well in Debian packaging. I'm assuming pandas doesn't really need to 
worry about which Qt API is being used in the testing and so any of them 
should be fine; if you do need to test with multiple APIs then looping 
over the API has become standard in various other qtpy* and pyqt* packages.

The code that actually uses Qt (oi/clipboard/) still talks a lot about 
Qt4... that's disturbing. That it's going via qtpy probably means it 
just works for Qt6 too though.

(of course the other option is to suppress testing the clipboard functions?)

cheers
Stuart


-- 
Stuart Prescott   http://www.nanonanonano.net/ stuart at nanonanonano.net
Debian Developer  http://www.debian.org/       stuart at debian.org
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